[pypy-commit] pypy numpy-dtype-refactor: Merged default in.

alex_gaynor noreply at buildbot.pypy.org
Thu Nov 24 16:54:21 CET 2011


Author: Alex Gaynor <alex.gaynor at gmail.com>
Branch: numpy-dtype-refactor
Changeset: r49741:a98e703d41e2
Date: 2011-11-24 09:54 -0600
http://bitbucket.org/pypy/pypy/changeset/a98e703d41e2/

Log:	Merged default in.

diff --git a/.hgtags b/.hgtags
--- a/.hgtags
+++ b/.hgtags
@@ -1,3 +1,4 @@
 b590cf6de4190623aad9aa698694c22e614d67b9 release-1.5
 b48df0bf4e75b81d98f19ce89d4a7dc3e1dab5e5 benchmarked
 d8ac7d23d3ec5f9a0fa1264972f74a010dbfd07f release-1.6
+ff4af8f318821f7f5ca998613a60fca09aa137da release-1.7
diff --git a/lib_pypy/_sqlite3.py b/lib_pypy/_sqlite3.py
--- a/lib_pypy/_sqlite3.py
+++ b/lib_pypy/_sqlite3.py
@@ -231,6 +231,9 @@
 sqlite.sqlite3_result_text.argtypes = [c_void_p, c_char_p, c_int, c_void_p]
 sqlite.sqlite3_result_text.restype = None
 
+sqlite.sqlite3_enable_load_extension.argtypes = [c_void_p, c_int]
+sqlite.sqlite3_enable_load_extension.restype = c_int
+
 ##########################################
 # END Wrapped SQLite C API and constants
 ##########################################
@@ -705,6 +708,14 @@
         from sqlite3.dump import _iterdump
         return _iterdump(self)
 
+    def enable_load_extension(self, enabled):
+        self._check_thread()
+        self._check_closed()
+
+        rc = sqlite.sqlite3_enable_load_extension(self.db, int(enabled))
+        if rc != SQLITE_OK:
+            raise OperationalError("Error enabling load extension")
+
 DML, DQL, DDL = range(3)
 
 class Cursor(object):
diff --git a/py/_code/code.py b/py/_code/code.py
--- a/py/_code/code.py
+++ b/py/_code/code.py
@@ -307,7 +307,7 @@
                     self._striptext = 'AssertionError: '
         self._excinfo = tup
         self.type, self.value, tb = self._excinfo
-        self.typename = self.type.__name__
+        self.typename = getattr(self.type, "__name__", "???")
         self.traceback = py.code.Traceback(tb)
 
     def __repr__(self):
diff --git a/pypy/config/pypyoption.py b/pypy/config/pypyoption.py
--- a/pypy/config/pypyoption.py
+++ b/pypy/config/pypyoption.py
@@ -281,6 +281,9 @@
                    "actually create the full list until the resulting "
                    "list is mutated",
                    default=False),
+        BoolOption("withliststrategies",
+                   "enable optimized ways to store lists of primitives ",
+                   default=True),
 
         BoolOption("withtypeversion",
                    "version type objects when changing them",
diff --git a/pypy/config/test/test_translationoption.py b/pypy/config/test/test_translationoption.py
new file mode 100644
--- /dev/null
+++ b/pypy/config/test/test_translationoption.py
@@ -0,0 +1,10 @@
+import py
+from pypy.config.translationoption import get_combined_translation_config
+from pypy.config.translationoption import set_opt_level
+from pypy.config.config import ConflictConfigError
+
+
+def test_no_gcrootfinder_with_boehm():
+    config = get_combined_translation_config()
+    config.translation.gcrootfinder = "shadowstack"
+    py.test.raises(ConflictConfigError, set_opt_level, config, '0')
diff --git a/pypy/config/translationoption.py b/pypy/config/translationoption.py
--- a/pypy/config/translationoption.py
+++ b/pypy/config/translationoption.py
@@ -398,6 +398,10 @@
     # make_sure_not_resized often relies on it, so we always enable them
     config.translation.suggest(list_comprehension_operations=True)
 
+    # finally, make the choice of the gc definitive.  This will fail
+    # if we have specified strange inconsistent settings.
+    config.translation.gc = config.translation.gc
+
 # ----------------------------------------------------------------
 
 def set_platform(config):
diff --git a/pypy/doc/coding-guide.rst b/pypy/doc/coding-guide.rst
--- a/pypy/doc/coding-guide.rst
+++ b/pypy/doc/coding-guide.rst
@@ -270,7 +270,12 @@
   - *slicing*:
     the slice start must be within bounds. The stop doesn't need to, but it must
     not be smaller than the start.  All negative indexes are disallowed, except for
-    the [:-1] special case.  No step.
+    the [:-1] special case.  No step.  Slice deletion follows the same rules.
+    
+  - *slice assignment*:
+    only supports ``lst[x:y] = sublist``, if ``len(sublist) == y - x``.
+    In other words, slice assignment cannot change the total length of the list,
+    but just replace items.
 
   - *other operators*:
     ``+``, ``+=``, ``in``, ``*``, ``*=``, ``==``, ``!=`` work as expected.
diff --git a/pypy/doc/config/objspace.std.withliststrategies.txt b/pypy/doc/config/objspace.std.withliststrategies.txt
new file mode 100644
--- /dev/null
+++ b/pypy/doc/config/objspace.std.withliststrategies.txt
@@ -0,0 +1,2 @@
+Enable list strategies: Use specialized representations for lists of primitive
+objects, such as ints.
diff --git a/pypy/doc/cpython_differences.rst b/pypy/doc/cpython_differences.rst
--- a/pypy/doc/cpython_differences.rst
+++ b/pypy/doc/cpython_differences.rst
@@ -262,6 +262,26 @@
 documented as such (as e.g. for hasattr()), in most cases PyPy
 lets the exception propagate instead.
 
+Object Identity of Primitive Values, ``is`` and ``id``
+-------------------------------------------------------
+
+Object identity of primitive values works by value equality, not by identity of
+the wrapper. This means that ``x + 1 is x + 1`` is always true, for arbitrary
+integers ``x``. The rule applies for the following types:
+
+ - ``int``
+
+ - ``float``
+
+ - ``long``
+
+ - ``complex``
+
+This change requires some changes to ``id`` as well. ``id`` fulfills the
+following condition: ``x is y <=> id(x) == id(y)``. Therefore ``id`` of the
+above types will return a value that is computed from the argument, and can
+thus be larger than ``sys.maxint`` (i.e. it can be an arbitrary long).
+
 
 Miscellaneous
 -------------
@@ -284,14 +304,5 @@
   never a dictionary as it sometimes is in CPython. Assigning to
   ``__builtins__`` has no effect.
 
-* Do not compare immutable objects with ``is``.  For example on CPython
-  it is true that ``x is 0`` works, i.e. does the same as ``type(x) is
-  int and x == 0``, but it is so by accident.  If you do instead
-  ``x is 1000``, then it stops working, because 1000 is too large and
-  doesn't come from the internal cache.  In PyPy it fails to work in
-  both cases, because we have no need for a cache at all.
-
-* Also, object identity of immutable keys in dictionaries is not necessarily
-  preserved.
 
 .. include:: _ref.txt
diff --git a/pypy/doc/how-to-release.rst b/pypy/doc/how-to-release.rst
--- a/pypy/doc/how-to-release.rst
+++ b/pypy/doc/how-to-release.rst
@@ -1,6 +1,3 @@
-.. include:: needswork.txt
-
-.. needs work, it talks about svn. also, it is not really user documentation
 
 Making a PyPy Release
 =======================
@@ -12,11 +9,8 @@
 forgetting things. A set of todo files may also work.
 
 Check and prioritize all issues for the release, postpone some if necessary,
-create new  issues also as necessary. A meeting (or meetings) should be
-organized to decide what things are priorities, should go in and work for
-the release. 
-
-An important thing is to get the documentation into an up-to-date state!
+create new  issues also as necessary. An important thing is to get
+the documentation into an up-to-date state!
 
 Release Steps
 ----------------
diff --git a/pypy/doc/project-ideas.rst b/pypy/doc/project-ideas.rst
--- a/pypy/doc/project-ideas.rst
+++ b/pypy/doc/project-ideas.rst
@@ -23,17 +23,20 @@
 PyPy's implementation of the Python ``long`` type is slower than CPython's.
 Find out why and optimize them.
 
+Make bytearray type fast
+------------------------
+
+PyPy's bytearray type is very inefficient. It would be an interesting
+task to look into possible optimizations on this.
+
 Numpy improvements
 ------------------
 
-This is more of a project-container than a single project. Possible ideas:
+The numpy is rapidly progressing in pypy, so feel free to come to IRC and
+ask for proposed topic. A not necesarilly up-to-date `list of topics`_
+is also available.
 
-* experiment with auto-vectorization using SSE or implement vectorization
-  without automatically detecting it for array operations.
-
-* improve numpy, for example implement memory views.
-
-* interface with fortran/C libraries.
+.. _`list of topics`: https://bitbucket.org/pypy/extradoc/src/extradoc/planning/micronumpy.txt
 
 Improving the jitviewer
 ------------------------
diff --git a/pypy/doc/release-1.7.0.rst b/pypy/doc/release-1.7.0.rst
--- a/pypy/doc/release-1.7.0.rst
+++ b/pypy/doc/release-1.7.0.rst
@@ -1,44 +1,94 @@
-=====================
-PyPy 1.7
-=====================
+==================================
+PyPy 1.7 - widening the sweet spot
+==================================
+
+We're pleased to announce the 1.7 release of PyPy. As became a habit, this
+release brings a lot of bugfixes and performance improvements over the 1.6
+release. However, unlike the previous releases, the focus has been on widening
+the "sweet spot" of PyPy. That is, classes of Python code that PyPy can greatly
+speed up should be vastly improved with this release. You can download the 1.7
+release here:
+
+    http://pypy.org/download.html
+
+What is PyPy?
+=============
+
+PyPy is a very compliant Python interpreter, almost a drop-in replacement for
+CPython 2.7. It's fast (`pypy 1.7 and cpython 2.7.1`_ performance comparison)
+due to its integrated tracing JIT compiler.
+
+This release supports x86 machines running Linux 32/64, Mac OS X 32/64 or
+Windows 32. Windows 64 work is ongoing, but not yet natively supported.
+
+The main topic of this release is widening the range of code which PyPy
+can greatly speed up. On average on
+our benchmark suite, PyPy 1.7 is around **30%** faster than PyPy 1.6 and up
+to **20 times** faster on some benchmarks.
+
+.. _`pypy 1.7 and cpython 2.7.1`: http://speed.pypy.org
+
 
 Highlights
 ==========
 
-* numerous performance improvements, PyPy 1.7 is xxx faster than 1.6
+* Numerous performance improvements. There are too many examples which python
+  constructs now should behave faster to list them.
 
-* numerous bugfixes, compatibility fixes
+* Bugfixes and compatibility fixes with CPython.
 
-* windows fixes
+* Windows fixes.
 
-* stackless and JIT integration
+* PyPy now comes with stackless features enabled by default. However,
+  any loop using stackless features will interrupt the JIT for now, so no real
+  performance improvement for stackless-based programs. Contact pypy-dev for
+  info how to help on removing this restriction.
 
-* numpy progress - dtypes, numpy -> numpypy renaming
+* NumPy effort in PyPy was renamed numpypy. In order to try using it, simply
+  write::
 
-* brand new JSON encoder
+    import numpypy as numpy
 
-* improved memory footprint on heavy users of C APIs example - tornado
+  at the beginning of your program. There is a huge progress on numpy in PyPy
+  since 1.6, the main feature being implementation of dtypes.
 
-* cpyext progress
+* JSON encoder (but not decoder) has been replaced with a new one. This one
+  is written in pure Python, but is known to outperform CPython's C extension
+  up to **2 times** in some cases. It's about **20 times** faster than
+  the one that we had in 1.6.
+
+* The memory footprint of some of our RPython modules has been drastically
+  improved. This should impact any applications using for example cryptography,
+  like tornado.
+
+* There was some progress in exposing even more CPython C API via cpyext.
 
 Things that didn't make it, expect in 1.8 soon
 ==============================================
 
-* list strategies
+There is an ongoing work, which while didn't make it to the release, is
+probably worth mentioning here. This is what you should probably expect in
+1.8 some time soon:
 
-* multi-dimensional arrays for numpy
+* Specialized list implementation. There is a branch that implements lists of
+  integers/floats/strings as compactly as array.array. This should drastically
+  improve performance/memory impact of some applications
 
-* ARM backend
+* NumPy effort is progressing forward, with multi-dimensional arrays coming
+  soon.
 
-* PPC backend
+* There are two brand new JIT assembler backends, notably for the PowerPC and
+  ARM processors.
 
-Things we're working on with unclear ETA
-========================================
+Fundraising
+===========
 
-* windows 64 (?)
+It's maybe worth mentioning that we're running fundraising campaigns for
+NumPy effort in PyPy and for Python 3 in PyPy. In case you want to see any
+of those happen faster, we urge you to donate to `numpy proposal`_ or
+`py3k proposal`_. In case you want PyPy to progress, but you trust us with
+the general direction, you can always donate to the `general pot`_.
 
-* Py3k
-
-* SSE for numpy
-
-* specialized objects
+.. _`numpy proposal`: http://pypy.org/numpydonate.html
+.. _`py3k proposal`: http://pypy.org/py3donate.html
+.. _`general pot`: http://pypy.org
diff --git a/pypy/interpreter/baseobjspace.py b/pypy/interpreter/baseobjspace.py
--- a/pypy/interpreter/baseobjspace.py
+++ b/pypy/interpreter/baseobjspace.py
@@ -879,6 +879,16 @@
         """
         return self.unpackiterable(w_iterable, expected_length)
 
+    def listview_str(self, w_list):
+        """ Return a list of unwrapped strings out of a list of strings. If the
+        argument is not a list or does not contain only strings, return None.
+        May return None anyway.
+        """
+        return None
+
+    def newlist_str(self, list_s):
+        return self.newlist([self.wrap(s) for s in list_s])
+
     @jit.unroll_safe
     def exception_match(self, w_exc_type, w_check_class):
         """Checks if the given exception type matches 'w_check_class'."""
diff --git a/pypy/interpreter/generator.py b/pypy/interpreter/generator.py
--- a/pypy/interpreter/generator.py
+++ b/pypy/interpreter/generator.py
@@ -1,8 +1,9 @@
+from pypy.interpreter.baseobjspace import Wrappable
 from pypy.interpreter.error import OperationError
-from pypy.interpreter.baseobjspace import Wrappable
 from pypy.interpreter.gateway import NoneNotWrapped
+from pypy.interpreter.pyopcode import LoopBlock
 from pypy.rlib import jit
-from pypy.interpreter.pyopcode import LoopBlock
+from pypy.rlib.objectmodel import specialize
 
 
 class GeneratorIterator(Wrappable):
@@ -156,38 +157,43 @@
                     break
                 block = block.previous
 
-    def unpack_into(self, results_w):
-        """This is a hack for performance: runs the generator and collects
-        all produced items in a list."""
-        # XXX copied and simplified version of send_ex()
-        space = self.space
-        if self.running:
-            raise OperationError(space.w_ValueError,
-                                 space.wrap('generator already executing'))
-        frame = self.frame
-        if frame is None:    # already finished
-            return
-        self.running = True
-        try:
-            pycode = self.pycode
-            while True:
-                jitdriver.jit_merge_point(self=self, frame=frame,
-                                          results_w=results_w,
-                                          pycode=pycode)
-                try:
-                    w_result = frame.execute_frame(space.w_None)
-                except OperationError, e:
-                    if not e.match(space, space.w_StopIteration):
-                        raise
-                    break
-                # if the frame is now marked as finished, it was RETURNed from
-                if frame.frame_finished_execution:
-                    break
-                results_w.append(w_result)     # YIELDed
-        finally:
-            frame.f_backref = jit.vref_None
-            self.running = False
-            self.frame = None
-
-jitdriver = jit.JitDriver(greens=['pycode'],
-                          reds=['self', 'frame', 'results_w'])
+    # Results can be either an RPython list of W_Root, or it can be an
+    # app-level W_ListObject, which also has an append() method, that's why we
+    # generate 2 versions of the function and 2 jit drivers.
+    def _create_unpack_into():
+        jitdriver = jit.JitDriver(greens=['pycode'],
+                                  reds=['self', 'frame', 'results'])
+        def unpack_into(self, results):
+            """This is a hack for performance: runs the generator and collects
+            all produced items in a list."""
+            # XXX copied and simplified version of send_ex()
+            space = self.space
+            if self.running:
+                raise OperationError(space.w_ValueError,
+                                     space.wrap('generator already executing'))
+            frame = self.frame
+            if frame is None:    # already finished
+                return
+            self.running = True
+            try:
+                pycode = self.pycode
+                while True:
+                    jitdriver.jit_merge_point(self=self, frame=frame,
+                                              results=results, pycode=pycode)
+                    try:
+                        w_result = frame.execute_frame(space.w_None)
+                    except OperationError, e:
+                        if not e.match(space, space.w_StopIteration):
+                            raise
+                        break
+                    # if the frame is now marked as finished, it was RETURNed from
+                    if frame.frame_finished_execution:
+                        break
+                    results.append(w_result)     # YIELDed
+            finally:
+                frame.f_backref = jit.vref_None
+                self.running = False
+                self.frame = None
+        return unpack_into
+    unpack_into = _create_unpack_into()
+    unpack_into_w = _create_unpack_into()
\ No newline at end of file
diff --git a/pypy/interpreter/test/test_function.py b/pypy/interpreter/test/test_function.py
--- a/pypy/interpreter/test/test_function.py
+++ b/pypy/interpreter/test/test_function.py
@@ -587,7 +587,7 @@
         assert isinstance(meth2, Method)
         assert meth2.call_args(args) == obj1
         # Check method returned from unbound_method.__get__()
-        w_meth3 = descr_function_get(space, func, None, space.type(obj2))
+        w_meth3 = descr_function_get(space, func, space.w_None, space.type(obj2))
         meth3 = space.unwrap(w_meth3)
         w_meth4 = meth3.descr_method_get(obj2, space.w_None)
         meth4 = space.unwrap(w_meth4)
diff --git a/pypy/interpreter/test/test_objspace.py b/pypy/interpreter/test/test_objspace.py
--- a/pypy/interpreter/test/test_objspace.py
+++ b/pypy/interpreter/test/test_objspace.py
@@ -63,10 +63,13 @@
     def test_unpackiterable(self):
         space = self.space
         w = space.wrap
-        l = [w(1), w(2), w(3), w(4)]
+        l = [space.newlist([]) for l in range(4)]
         w_l = space.newlist(l)
-        assert space.unpackiterable(w_l) == l
-        assert space.unpackiterable(w_l, 4) == l
+        l1 = space.unpackiterable(w_l)
+        l2 = space.unpackiterable(w_l, 4)
+        for i in range(4):
+            assert space.is_w(l1[i], l[i])
+            assert space.is_w(l2[i], l[i])
         err = raises(OperationError, space.unpackiterable, w_l, 3)
         assert err.value.match(space, space.w_ValueError)
         err = raises(OperationError, space.unpackiterable, w_l, 5)
diff --git a/pypy/jit/metainterp/optimizeopt/optimizer.py b/pypy/jit/metainterp/optimizeopt/optimizer.py
--- a/pypy/jit/metainterp/optimizeopt/optimizer.py
+++ b/pypy/jit/metainterp/optimizeopt/optimizer.py
@@ -348,6 +348,7 @@
         self.opaque_pointers = {}
         self.replaces_guard = {}
         self._newoperations = []
+        self.seen_results = {}
         self.optimizer = self
         self.optpure = None
         self.optearlyforce = None
@@ -542,6 +543,10 @@
                 op = self.store_final_boxes_in_guard(op)
         elif op.can_raise():
             self.exception_might_have_happened = True
+        if op.result:
+            if op.result in self.seen_results:
+                raise ValueError, "invalid optimization"
+            self.seen_results[op.result] = None
         self._newoperations.append(op)
 
     def replace_op(self, old_op, new_op):
diff --git a/pypy/jit/metainterp/optimizeopt/test/test_optimizeopt.py b/pypy/jit/metainterp/optimizeopt/test/test_optimizeopt.py
--- a/pypy/jit/metainterp/optimizeopt/test/test_optimizeopt.py
+++ b/pypy/jit/metainterp/optimizeopt/test/test_optimizeopt.py
@@ -1191,6 +1191,75 @@
         """
         self.optimize_loop(ops, expected, preamble)
 
+    def test_virtual_recursive(self):
+        ops = """
+        [p0]
+        p41 = getfield_gc(p0, descr=nextdescr)
+        i0 = getfield_gc(p41, descr=valuedescr)
+        p1 = new_with_vtable(ConstClass(node_vtable2))
+        p2 = new_with_vtable(ConstClass(node_vtable2))
+        setfield_gc(p2, p1, descr=nextdescr)
+        setfield_gc(p1, p2, descr=nextdescr)
+        i1 = int_add(i0, 1)
+        setfield_gc(p2, i1, descr=valuedescr)
+        jump(p1)
+        """
+        preamble = """
+        [p0]
+        p41 = getfield_gc(p0, descr=nextdescr)
+        i0 = getfield_gc(p41, descr=valuedescr)
+        i3 = int_add(i0, 1)
+        jump(i3)
+        """
+        expected = """
+        [i0]
+        i1 = int_add(i0, 1)
+        jump(i1)
+        """
+        self.optimize_loop(ops, expected, preamble)
+
+    def test_virtual_recursive_forced(self):
+        ops = """
+        [p0]
+        p41 = getfield_gc(p0, descr=nextdescr)
+        i0 = getfield_gc(p41, descr=valuedescr)
+        p1 = new_with_vtable(ConstClass(node_vtable2))
+        p2 = new_with_vtable(ConstClass(node_vtable2))
+        setfield_gc(p2, p1, descr=nextdescr)
+        setfield_gc(p1, p2, descr=nextdescr)
+        i1 = int_add(i0, 1)
+        setfield_gc(p2, i1, descr=valuedescr)
+        setfield_gc(p0, p1, descr=nextdescr)
+        jump(p1)
+        """
+        preamble = """
+        [p0]
+        p41 = getfield_gc(p0, descr=nextdescr)
+        i0 = getfield_gc(p41, descr=valuedescr)
+        i1 = int_add(i0, 1)
+        p1 = new_with_vtable(ConstClass(node_vtable2))
+        p2 = new_with_vtable(ConstClass(node_vtable2))
+        setfield_gc(p2, i1, descr=valuedescr)
+        setfield_gc(p2, p1, descr=nextdescr)
+        setfield_gc(p1, p2, descr=nextdescr)
+        setfield_gc(p0, p1, descr=nextdescr)
+        jump(p1)
+        """
+        loop = """
+        [p0]
+        p41 = getfield_gc(p0, descr=nextdescr)
+        i0 = getfield_gc(p41, descr=valuedescr)
+        i1 = int_add(i0, 1)
+        p1 = new_with_vtable(ConstClass(node_vtable2))
+        p2 = new_with_vtable(ConstClass(node_vtable2))
+        setfield_gc(p0, p1, descr=nextdescr)
+        setfield_gc(p2, p1, descr=nextdescr)
+        setfield_gc(p1, p2, descr=nextdescr)
+        setfield_gc(p2, i1, descr=valuedescr)
+        jump(p1)
+        """
+        self.optimize_loop(ops, loop, preamble)
+
     def test_virtual_constant_isnull(self):
         ops = """
         [i0]
@@ -5438,6 +5507,96 @@
         jump()
         """
         self.optimize_loop(ops, expected)
+        # ----------
+        ops = """
+        [p1]
+        p0 = new_with_vtable(ConstClass(ptrobj_immut_vtable))
+        setfield_gc(p0, p1, descr=immut_ptrval)
+        escape(p0)
+        jump(p1)
+        """
+        self.optimize_loop(ops, ops)
+        # ----------
+        ops = """
+        []
+        p0 = new_with_vtable(ConstClass(ptrobj_immut_vtable))
+        p1 = new_with_vtable(ConstClass(intobj_immut_vtable))
+        setfield_gc(p1, 1242, descr=immut_intval)
+        setfield_gc(p0, p1, descr=immut_ptrval)
+        escape(p0)
+        jump()
+        """
+        class PtrObj1242(object):
+            _TYPE = llmemory.GCREF.TO
+            def __eq__(slf, other):
+                if slf is other:
+                    return 1
+                p1 = other.container.ptrval
+                p1cast = lltype.cast_pointer(lltype.Ptr(self.INTOBJ_IMMUT), p1)
+                return p1cast.intval == 1242
+        self.namespace['ptrobj1242'] = lltype._ptr(llmemory.GCREF,
+                                                   PtrObj1242())
+        expected = """
+        []
+        escape(ConstPtr(ptrobj1242))
+        jump()
+        """
+        self.optimize_loop(ops, expected)
+
+    def test_immutable_constantfold_recursive(self):
+        ops = """
+        []
+        p0 = new_with_vtable(ConstClass(ptrobj_immut_vtable))
+        setfield_gc(p0, p0, descr=immut_ptrval)
+        escape(p0)
+        jump()
+        """
+        from pypy.rpython.lltypesystem import lltype, llmemory
+        class PtrObjSelf(object):
+            _TYPE = llmemory.GCREF.TO
+            def __eq__(slf, other):
+                if slf is other:
+                    return 1
+                p1 = other.container.ptrval
+                p1cast = lltype.cast_pointer(lltype.Ptr(self.PTROBJ_IMMUT), p1)
+                return p1cast.ptrval == p1
+        self.namespace['ptrobjself'] = lltype._ptr(llmemory.GCREF,
+                                                   PtrObjSelf())
+        expected = """
+        []
+        escape(ConstPtr(ptrobjself))
+        jump()
+        """
+        self.optimize_loop(ops, expected)
+        #
+        ops = """
+        []
+        p0 = new_with_vtable(ConstClass(ptrobj_immut_vtable))
+        p1 = new_with_vtable(ConstClass(ptrobj_immut_vtable))
+        setfield_gc(p0, p1, descr=immut_ptrval)
+        setfield_gc(p1, p0, descr=immut_ptrval)
+        escape(p0)
+        jump()
+        """
+        class PtrObjSelf2(object):
+            _TYPE = llmemory.GCREF.TO
+            def __eq__(slf, other):
+                if slf is other:
+                    return 1
+                p1 = other.container.ptrval
+                p1cast = lltype.cast_pointer(lltype.Ptr(self.PTROBJ_IMMUT), p1)
+                p2 = p1cast.ptrval
+                assert p2 != p1
+                p2cast = lltype.cast_pointer(lltype.Ptr(self.PTROBJ_IMMUT), p2)
+                return p2cast.ptrval == p1
+        self.namespace['ptrobjself2'] = lltype._ptr(llmemory.GCREF,
+                                                    PtrObjSelf2())
+        expected = """
+        []
+        escape(ConstPtr(ptrobjself2))
+        jump()
+        """
+        self.optimize_loop(ops, expected)
 
     # ----------
     def optimize_strunicode_loop(self, ops, optops, preamble):
diff --git a/pypy/jit/metainterp/optimizeopt/test/test_util.py b/pypy/jit/metainterp/optimizeopt/test/test_util.py
--- a/pypy/jit/metainterp/optimizeopt/test/test_util.py
+++ b/pypy/jit/metainterp/optimizeopt/test/test_util.py
@@ -139,6 +139,12 @@
     noimmut_intval = cpu.fielddescrof(INTOBJ_NOIMMUT, 'intval')
     immut_intval = cpu.fielddescrof(INTOBJ_IMMUT, 'intval')
 
+    PTROBJ_IMMUT = lltype.GcStruct('PTROBJ_IMMUT', ('parent', OBJECT),
+                                            ('ptrval', lltype.Ptr(OBJECT)),
+                                            hints={'immutable': True})
+    ptrobj_immut_vtable = lltype.malloc(OBJECT_VTABLE, immortal=True)
+    immut_ptrval = cpu.fielddescrof(PTROBJ_IMMUT, 'ptrval')
+
     arraydescr = cpu.arraydescrof(lltype.GcArray(lltype.Signed))
     floatarraydescr = cpu.arraydescrof(lltype.GcArray(lltype.Float))
 
@@ -246,6 +252,7 @@
     register_known_gctype(cpu, jit_virtual_ref_vtable,vrefinfo.JIT_VIRTUAL_REF)
     register_known_gctype(cpu, intobj_noimmut_vtable, INTOBJ_NOIMMUT)
     register_known_gctype(cpu, intobj_immut_vtable,   INTOBJ_IMMUT)
+    register_known_gctype(cpu, ptrobj_immut_vtable,   PTROBJ_IMMUT)
 
     namespace = locals()
 
diff --git a/pypy/jit/metainterp/optimizeopt/virtualize.py b/pypy/jit/metainterp/optimizeopt/virtualize.py
--- a/pypy/jit/metainterp/optimizeopt/virtualize.py
+++ b/pypy/jit/metainterp/optimizeopt/virtualize.py
@@ -87,14 +87,36 @@
     def _get_descr(self):
         raise NotImplementedError
 
-    def _is_immutable_and_filled_with_constants(self, optforce):
+    def _is_immutable_and_filled_with_constants(self, memo=None):
+        # check if it is possible to force the given structure into a
+        # compile-time constant: this is allowed only if it is declared
+        # immutable, if all fields are already filled, and if each field
+        # is either a compile-time constant or (recursively) a structure
+        # which also answers True to the same question.
+        #
+        # check that all fields are filled.  The following equality check
+        # also fails if count == -1, meaning "not an immutable at all".
         count = self._get_descr().count_fields_if_immutable()
-        if count != len(self._fields):    # always the case if count == -1
+        if count != len(self._fields):
             return False
+        #
+        # initialize 'memo'
+        if memo is None:
+            memo = {}
+        elif self in memo:
+            return True   # recursive case: assume yes
+        memo[self] = None
+        #
         for value in self._fields.itervalues():
-            subbox = value.force_box(optforce)
-            if not isinstance(subbox, Const):
-                return False
+            if value.is_constant():
+                pass            # it is a constant value: ok
+            elif (isinstance(value, AbstractVirtualStructValue)
+                  and value.is_virtual()):
+                # recursive check
+                if not value._is_immutable_and_filled_with_constants(memo):
+                    return False
+            else:
+                return False    # not a constant at all
         return True
 
     def force_at_end_of_preamble(self, already_forced, optforce):
@@ -114,7 +136,7 @@
         if not we_are_translated():
             op.name = 'FORCE ' + self.source_op.name
 
-        if self._is_immutable_and_filled_with_constants(optforce):
+        if self._is_immutable_and_filled_with_constants():
             box = optforce.optimizer.constant_fold(op)
             self.make_constant(box)
             for ofs, value in self._fields.iteritems():
diff --git a/pypy/jit/metainterp/test/test_tracingopts.py b/pypy/jit/metainterp/test/test_tracingopts.py
--- a/pypy/jit/metainterp/test/test_tracingopts.py
+++ b/pypy/jit/metainterp/test/test_tracingopts.py
@@ -593,6 +593,32 @@
         res = self.interp_operations(fn, [sys.maxint])
         assert res == 12
 
+    def test_opaque_list(self):
+        from pypy.rlib.rerased import new_erasing_pair
+        erase, unerase = new_erasing_pair("test_opaque_list")
+        def fn(n, ca, cb):
+            l1 = [n]
+            l2 = [n]
+            a1 = erase(l1)
+            a2 = erase(l1)
+            a = a1
+            if ca:
+                a = a2
+                if n < -100:
+                    unerase(a).append(5)
+            b = a1
+            if cb:
+                b = a
+            return unerase(a)[0] + unerase(b)[0]
+        res = self.interp_operations(fn, [7, 0, 1])
+        assert res == 7 * 2
+        self.check_operations_history(getarrayitem_gc=0,
+                getfield_gc=0)
+        res = self.interp_operations(fn, [-7, 1, 1])
+        assert res == -7 * 2
+        self.check_operations_history(getarrayitem_gc=0,
+                getfield_gc=0)
+
     def test_copy_str_content(self):
         def fn(n):
             a = StringBuilder()
@@ -601,4 +627,4 @@
             return x[0]
         res = self.interp_operations(fn, [0])
         assert res == 1
-        self.check_operations_history(getarrayitem_gc=0, getarrayitem_gc_pure=0 )
\ No newline at end of file
+        self.check_operations_history(getarrayitem_gc=0, getarrayitem_gc_pure=0)
diff --git a/pypy/module/__builtin__/functional.py b/pypy/module/__builtin__/functional.py
--- a/pypy/module/__builtin__/functional.py
+++ b/pypy/module/__builtin__/functional.py
@@ -95,17 +95,17 @@
     return space.newlist(res_w)
 
 
-def range_withspecialized_implementation(space, start, step, howmany):
+def range_withspecialized_implementation(space, start, step, length):
     assert space.config.objspace.std.withrangelist
-    from pypy.objspace.std.rangeobject import W_RangeListObject
-    return W_RangeListObject(start, step, howmany)
+    from pypy.objspace.std.listobject import make_range_list
+    return make_range_list(space, start, step, length)
 
 bigint_one = rbigint.fromint(1)
 
 def range_with_longs(space, w_start, w_stop, w_step):
 
     start = lo = space.bigint_w(w_start)
-    stop  = hi = space.bigint_w(w_stop)
+    hi = space.bigint_w(w_stop)
     step  = st = space.bigint_w(w_step)
 
     if not step.tobool():
diff --git a/pypy/module/_weakref/interp__weakref.py b/pypy/module/_weakref/interp__weakref.py
--- a/pypy/module/_weakref/interp__weakref.py
+++ b/pypy/module/_weakref/interp__weakref.py
@@ -1,7 +1,7 @@
 import py
 from pypy.interpreter.baseobjspace import Wrappable, W_Root
 from pypy.interpreter.error import OperationError
-from pypy.interpreter.gateway import interp2app, ObjSpace
+from pypy.interpreter.gateway import interp2app, ObjSpace, NoneNotWrapped
 from pypy.interpreter.typedef import TypeDef
 from pypy.rlib import jit
 import weakref
@@ -294,11 +294,11 @@
     lifeline = getlifelinewithcallbacks(space, w_obj)
     return lifeline.make_proxy_with_callback(w_obj, w_callable)
 
-def proxy(space, w_obj, w_callable=None):
+def proxy(space, w_obj, w_callable=NoneNotWrapped):
     """Create a proxy object that weakly references 'obj'.
 'callback', if given, is called with the proxy as an argument when 'obj'
 is about to be finalized."""
-    if space.is_w(w_callable, space.w_None):
+    if w_callable is None:
         return get_or_make_proxy(space, w_obj)
     else:
         return make_proxy_with_callback(space, w_obj, w_callable)
diff --git a/pypy/module/cpyext/listobject.py b/pypy/module/cpyext/listobject.py
--- a/pypy/module/cpyext/listobject.py
+++ b/pypy/module/cpyext/listobject.py
@@ -32,7 +32,7 @@
     Py_DecRef(space, w_item)
     if not isinstance(w_list, W_ListObject):
         PyErr_BadInternalCall(space)
-    wrappeditems = w_list.wrappeditems
+    wrappeditems = w_list.getitems()
     if index < 0 or index >= len(wrappeditems):
         raise OperationError(space.w_IndexError, space.wrap(
             "list assignment index out of range"))
@@ -47,7 +47,7 @@
     IndexError exception."""
     if not isinstance(w_list, W_ListObject):
         PyErr_BadInternalCall(space)
-    wrappeditems = w_list.wrappeditems
+    wrappeditems = w_list.getitems()
     if index < 0 or index >= len(wrappeditems):
         raise OperationError(space.w_IndexError, space.wrap(
             "list index out of range"))
@@ -74,7 +74,7 @@
     """Macro form of PyList_Size() without error checking.
     """
     assert isinstance(w_list, W_ListObject)
-    return len(w_list.wrappeditems)
+    return len(w_list.getitems())
 
 
 @cpython_api([PyObject], Py_ssize_t, error=-1)
diff --git a/pypy/module/cpyext/sequence.py b/pypy/module/cpyext/sequence.py
--- a/pypy/module/cpyext/sequence.py
+++ b/pypy/module/cpyext/sequence.py
@@ -56,7 +56,7 @@
     PySequence_Fast(), o is not NULL, and that i is within bounds.
     """
     if isinstance(w_obj, listobject.W_ListObject):
-        w_res = w_obj.wrappeditems[index]
+        w_res = w_obj.getitem(index)
     else:
         assert isinstance(w_obj, tupleobject.W_TupleObject)
         w_res = w_obj.wrappeditems[index]
@@ -70,7 +70,7 @@
     PySequence_Fast_GET_SIZE() is faster because it can assume o is a list
     or tuple."""
     if isinstance(w_obj, listobject.W_ListObject):
-        return len(w_obj.wrappeditems)
+        return w_obj.length()
     assert isinstance(w_obj, tupleobject.W_TupleObject)
     return len(w_obj.wrappeditems)
 
diff --git a/pypy/module/gc/test/test_referents.py b/pypy/module/gc/test/test_referents.py
--- a/pypy/module/gc/test/test_referents.py
+++ b/pypy/module/gc/test/test_referents.py
@@ -7,9 +7,13 @@
         from pypy.rlib import rgc
         cls._backup = [rgc.get_rpy_roots]
         w = cls.space.wrap
+        space = cls.space
         class RandomRPythonObject(object):
             pass
-        cls.ALL_ROOTS = [w(4), w([2, 7]), RandomRPythonObject()]
+        l4 = space.newlist([w(4)])
+        l2 = space.newlist([w(2)])
+        l7 = space.newlist([w(7)])
+        cls.ALL_ROOTS = [l4, space.newlist([l2, l7]), RandomRPythonObject()]
         cls.w_ALL_ROOTS = cls.space.newlist(cls.ALL_ROOTS)
         rgc.get_rpy_roots = lambda: (
             map(rgc._GcRef, cls.ALL_ROOTS) + [rgc.NULL_GCREF]*17)
@@ -41,14 +45,14 @@
         if self.runappdirect:
             pass    # unsure what to test
         else:
-            assert lst[0] == 4
-            assert lst[1] == [2, 7]
+            assert lst[0] == [4]
+            assert lst[1] == [[2], [7]]
             assert type(lst[2]) is gc.GcRef
             assert len(lst) == 3
 
     def test_get_rpy_referents(self):
         import gc
-        y = 12345
+        y = [12345]
         x = [y]
         lst = gc.get_rpy_referents(x)
         # After translation, 'lst' should contain the RPython-level list
@@ -88,8 +92,8 @@
 
     def test_get_referents(self):
         import gc
-        y = 12345
-        z = 23456
+        y = [12345]
+        z = [23456]
         x = [y, z]
         lst = gc.get_referents(x)
         assert y in lst and z in lst
diff --git a/pypy/module/micronumpy/__init__.py b/pypy/module/micronumpy/__init__.py
--- a/pypy/module/micronumpy/__init__.py
+++ b/pypy/module/micronumpy/__init__.py
@@ -5,7 +5,7 @@
     applevel_name = 'numpypy'
 
     interpleveldefs = {
-        'array': 'interp_numarray.SingleDimArray',
+        'array': 'interp_numarray.NDimArray',
         'dtype': 'interp_dtype.W_Dtype',
         'ufunc': 'interp_ufuncs.W_Ufunc',
 
diff --git a/pypy/module/micronumpy/compile.py b/pypy/module/micronumpy/compile.py
--- a/pypy/module/micronumpy/compile.py
+++ b/pypy/module/micronumpy/compile.py
@@ -3,11 +3,13 @@
 It should not be imported by the module itself
 """
 
+import re
+
 from pypy.interpreter.baseobjspace import InternalSpaceCache, W_Root
 from pypy.module.micronumpy import interp_boxes
 from pypy.module.micronumpy.interp_dtype import get_dtype_cache
 from pypy.module.micronumpy.interp_numarray import (Scalar, BaseArray,
-     descr_new_array, scalar_w, SingleDimArray)
+     descr_new_array, scalar_w, NDimArray)
 from pypy.module.micronumpy import interp_ufuncs
 from pypy.rlib.objectmodel import specialize, instantiate
 
@@ -24,11 +26,18 @@
 class WrongFunctionName(Exception):
     pass
 
+class TokenizerError(Exception):
+    pass
+
+class BadToken(Exception):
+    pass
+
 SINGLE_ARG_FUNCTIONS = ["sum", "prod", "max", "min", "all", "any", "unegative"]
 
 class FakeSpace(object):
     w_ValueError = None
     w_TypeError = None
+    w_IndexError = None
     w_None = None
 
     w_bool = "bool"
@@ -37,19 +46,31 @@
     w_list = "list"
     w_long = "long"
     w_tuple = 'tuple'
+    w_slice = "slice"
 
     def __init__(self):
         """NOT_RPYTHON"""
         self.fromcache = InternalSpaceCache(self).getorbuild
 
     def issequence_w(self, w_obj):
-        return isinstance(w_obj, ListObject) or isinstance(w_obj, SingleDimArray)
+        return isinstance(w_obj, ListObject) or isinstance(w_obj, NDimArray)
 
     def isinstance_w(self, w_obj, w_tp):
-        return False
+        return w_obj.tp == w_tp
 
     def decode_index4(self, w_idx, size):
-        return (self.int_w(self.int(w_idx)), 0, 0, 1)
+        if isinstance(w_idx, IntObject):
+            return (self.int_w(w_idx), 0, 0, 1)
+        else:
+            assert isinstance(w_idx, SliceObject)
+            start, stop, step = w_idx.start, w_idx.stop, w_idx.step
+            if step == 0:
+                return (0, size, 1, size)
+            if start < 0:
+                start += size
+            if stop < 0:
+                stop += size
+            return (start, stop, step, size//step)
 
     @specialize.argtype(1)
     def wrap(self, obj):
@@ -59,7 +80,9 @@
             return BoolObject(obj)
         elif isinstance(obj, int):
             return IntObject(obj)
-        raise Exception
+        elif isinstance(obj, W_Root):
+            return obj
+        raise NotImplementedError
 
     def newlist(self, items):
         return ListObject(items)
@@ -67,6 +90,7 @@
     def listview(self, obj):
         assert isinstance(obj, ListObject)
         return obj.items
+    fixedview = listview
 
     def float(self, w_obj):
         if isinstance(w_obj, FloatObject):
@@ -115,6 +139,12 @@
     def allocate_instance(self, klass, w_subtype):
         return instantiate(klass)
 
+    def len_w(self, w_obj):
+        if isinstance(w_obj, ListObject):
+            return len(w_obj.items)
+        # XXX array probably
+        assert False
+
 class FloatObject(W_Root):
     tp = FakeSpace.w_float
     def __init__(self, floatval):
@@ -135,6 +165,13 @@
     def __init__(self, items):
         self.items = items
 
+class SliceObject(W_Root):
+    tp = FakeSpace.w_slice
+    def __init__(self, start, stop, step):
+        self.start = start
+        self.stop = stop
+        self.step = step
+
 class InterpreterState(object):
     def __init__(self, code):
         self.code = code
@@ -169,7 +206,7 @@
         interp.variables[self.name] = self.expr.execute(interp)
 
     def __repr__(self):
-        return "%% = %r" % (self.name, self.expr)
+        return "%r = %r" % (self.name, self.expr)
 
 class ArrayAssignment(Node):
     def __init__(self, name, index, expr):
@@ -179,19 +216,22 @@
 
     def execute(self, interp):
         arr = interp.variables[self.name]
-        w_index = self.index.execute(interp)
-        assert isinstance(w_index, BaseArray)
-        w_val = self.expr.execute(interp)
-        assert isinstance(w_val, BaseArray)
         assert isinstance(arr, BaseArray)
-        arr.descr_setitem(interp.space, w_index.eval(0), w_val.eval(0))
+        w_index = self.index.execute(interp).eval(arr.start_iter())
+        # cast to int
+        if isinstance(w_index, FloatObject):
+            w_index = IntObject(int(w_index.floatval))
+        elif isinstance(w_index, interp_boxes.W_Float64Box):
+            w_index = IntObject(int(w_index.value))
+        w_val = self.expr.execute(interp).eval(arr.start_iter())
+        arr.descr_setitem(interp.space, w_index, w_val)
 
     def __repr__(self):
         return "%s[%r] = %r" % (self.name, self.index, self.expr)
 
 class Variable(Node):
     def __init__(self, name):
-        self.name = name
+        self.name = name.strip(" ")
 
     def execute(self, interp):
         return interp.variables[self.name]
@@ -207,11 +247,11 @@
 
     def execute(self, interp):
         w_lhs = self.lhs.execute(interp)
+        if isinstance(self.rhs, SliceConstant):
+            w_rhs = self.rhs.wrap(interp.space)
+        else:
+            w_rhs = self.rhs.execute(interp)
         assert isinstance(w_lhs, BaseArray)
-        if isinstance(self.rhs, SliceConstant):
-            # XXX interface has changed on multidim branch
-            raise NotImplementedError
-        w_rhs = self.rhs.execute(interp)
         if self.name == '+':
             w_res = w_lhs.descr_add(interp.space, w_rhs)
         elif self.name == '*':
@@ -220,11 +260,8 @@
             w_res = w_lhs.descr_sub(interp.space, w_rhs)
         elif self.name == '->':
             if isinstance(w_rhs, Scalar):
-                index = int(interp.space.float_w(interp.space.float(w_rhs.value)))
-                dtype = get_dtype_cache(interp.space).w_float64dtype
-                return Scalar(dtype, w_lhs.get_concrete().eval(index))
-            else:
-                raise NotImplementedError
+                w_rhs = w_rhs.eval(w_rhs.start_iter()).descr_int(interp.space)
+            w_res = w_lhs.descr_getitem(interp.space, w_rhs)
         else:
             raise NotImplementedError
         if (not isinstance(w_res, BaseArray) and
@@ -259,7 +296,8 @@
             [interp.space.wrap(float(i)) for i in range(self.v)]
         )
         dtype = get_dtype_cache(interp.space).w_float64dtype
-        return descr_new_array(interp.space, None, w_list, w_dtype=dtype)
+        return descr_new_array(interp.space, None, w_list, w_dtype=dtype,
+                               w_order=None)
 
     def __repr__(self):
         return 'Range(%s)' % self.v
@@ -281,17 +319,24 @@
     def execute(self, interp):
         w_list = self.wrap(interp.space)
         dtype = get_dtype_cache(interp.space).w_float64dtype
-        return descr_new_array(interp.space, None, w_list, w_dtype=dtype)
+        return descr_new_array(interp.space, None, w_list, w_dtype=dtype,
+                               w_order=None)
 
     def __repr__(self):
         return "[" + ", ".join([repr(item) for item in self.items]) + "]"
 
 class SliceConstant(Node):
-    def __init__(self):
-        pass
+    def __init__(self, start, stop, step):
+        # no negative support for now
+        self.start = start
+        self.stop = stop
+        self.step = step
+
+    def wrap(self, space):
+        return SliceObject(self.start, self.stop, self.step)
 
     def __repr__(self):
-        return 'slice()'
+        return 'slice(%s,%s,%s)' % (self.start, self.stop, self.step)
 
 class Execute(Node):
     def __init__(self, expr):
@@ -305,7 +350,7 @@
 
 class FunctionCall(Node):
     def __init__(self, name, args):
-        self.name = name
+        self.name = name.strip(" ")
         self.args = args
 
     def __repr__(self):
@@ -350,95 +395,172 @@
         else:
             raise WrongFunctionName
 
+_REGEXES = [
+    ('-?[\d\.]+', 'number'),
+    ('\[', 'array_left'),
+    (':', 'colon'),
+    ('\w+', 'identifier'),
+    ('\]', 'array_right'),
+    ('(->)|[\+\-\*\/]', 'operator'),
+    ('=', 'assign'),
+    (',', 'coma'),
+    ('\|', 'pipe'),
+    ('\(', 'paren_left'),
+    ('\)', 'paren_right'),
+]
+REGEXES = []
+
+for r, name in _REGEXES:
+    REGEXES.append((re.compile(r' *(' + r + ')'), name))
+del _REGEXES
+
+class Token(object):
+    def __init__(self, name, v):
+        self.name = name
+        self.v = v
+
+    def __repr__(self):
+        return '(%s, %s)' % (self.name, self.v)
+
+empty = Token('', '')
+
+class TokenStack(object):
+    def __init__(self, tokens):
+        self.tokens = tokens
+        self.c = 0
+
+    def pop(self):
+        token = self.tokens[self.c]
+        self.c += 1
+        return token
+
+    def get(self, i):
+        if self.c + i >= len(self.tokens):
+            return empty
+        return self.tokens[self.c + i]
+
+    def remaining(self):
+        return len(self.tokens) - self.c
+
+    def push(self):
+        self.c -= 1
+
+    def __repr__(self):
+        return repr(self.tokens[self.c:])
+
 class Parser(object):
-    def parse_identifier(self, id):
-        id = id.strip(" ")
-        #assert id.isalpha()
-        return Variable(id)
+    def tokenize(self, line):
+        tokens = []
+        while True:
+            for r, name in REGEXES:
+                m = r.match(line)
+                if m is not None:
+                    g = m.group(0)
+                    tokens.append(Token(name, g))
+                    line = line[len(g):]
+                    if not line:
+                        return TokenStack(tokens)
+                    break
+            else:
+                raise TokenizerError(line)
 
-    def parse_expression(self, expr):
-        tokens = [i for i in expr.split(" ") if i]
-        if len(tokens) == 1:
-            return self.parse_constant_or_identifier(tokens[0])
+    def parse_number_or_slice(self, tokens):
+        start_tok = tokens.pop()
+        if start_tok.name == 'colon':
+            start = 0
+        else:
+            if tokens.get(0).name != 'colon':
+                return FloatConstant(start_tok.v)
+            start = int(start_tok.v)
+            tokens.pop()
+        if not tokens.get(0).name in ['colon', 'number']:
+            stop = -1
+            step = 1
+        else:
+            next = tokens.pop()
+            if next.name == 'colon':
+                stop = -1
+                step = int(tokens.pop().v)
+            else:
+                stop = int(next.v)
+                if tokens.get(0).name == 'colon':
+                    tokens.pop()
+                    step = int(tokens.pop().v)
+                else:
+                    step = 1
+        return SliceConstant(start, stop, step)
+
+
+    def parse_expression(self, tokens):
         stack = []
-        tokens.reverse()
-        while tokens:
+        while tokens.remaining():
             token = tokens.pop()
-            if token == ')':
-                raise NotImplementedError
-            elif self.is_identifier_or_const(token):
-                if stack:
-                    name = stack.pop().name
-                    lhs = stack.pop()
-                    rhs = self.parse_constant_or_identifier(token)
-                    stack.append(Operator(lhs, name, rhs))
+            if token.name == 'identifier':
+                if tokens.remaining() and tokens.get(0).name == 'paren_left':
+                    stack.append(self.parse_function_call(token.v, tokens))
                 else:
-                    stack.append(self.parse_constant_or_identifier(token))
+                    stack.append(Variable(token.v))
+            elif token.name == 'array_left':
+                stack.append(ArrayConstant(self.parse_array_const(tokens)))
+            elif token.name == 'operator':
+                stack.append(Variable(token.v))
+            elif token.name == 'number' or token.name == 'colon':
+                tokens.push()
+                stack.append(self.parse_number_or_slice(tokens))
+            elif token.name == 'pipe':
+                stack.append(RangeConstant(tokens.pop().v))
+                end = tokens.pop()
+                assert end.name == 'pipe'
             else:
-                stack.append(Variable(token))
-        assert len(stack) == 1
-        return stack[-1]
+                tokens.push()
+                break
+        stack.reverse()
+        lhs = stack.pop()
+        while stack:
+            op = stack.pop()
+            assert isinstance(op, Variable)
+            rhs = stack.pop()
+            lhs = Operator(lhs, op.name, rhs)
+        return lhs
 
-    def parse_constant(self, v):
-        lgt = len(v)-1
-        assert lgt >= 0
-        if ':' in v:
-            # a slice
-            assert v == ':'
-            return SliceConstant()
-        if v[0] == '[':
-            return ArrayConstant([self.parse_constant(elem)
-                                  for elem in v[1:lgt].split(",")])
-        if v[0] == '|':
-            return RangeConstant(v[1:lgt])
-        return FloatConstant(v)
-
-    def is_identifier_or_const(self, v):
-        c = v[0]
-        if ((c >= 'a' and c <= 'z') or (c >= 'A' and c <= 'Z') or
-            (c >= '0' and c <= '9') or c in '-.[|:'):
-            if v == '-' or v == "->":
-                return False
-            return True
-        return False
-
-    def parse_function_call(self, v):
-        l = v.split('(')
-        assert len(l) == 2
-        name = l[0]
-        cut = len(l[1]) - 1
-        assert cut >= 0
-        args = [self.parse_constant_or_identifier(id)
-                for id in l[1][:cut].split(",")]
+    def parse_function_call(self, name, tokens):
+        args = []
+        tokens.pop() # lparen
+        while tokens.get(0).name != 'paren_right':
+            args.append(self.parse_expression(tokens))
         return FunctionCall(name, args)
 
-    def parse_constant_or_identifier(self, v):
-        c = v[0]
-        if (c >= 'a' and c <= 'z') or (c >= 'A' and c <= 'Z'):
-            if '(' in v:
-                return self.parse_function_call(v)
-            return self.parse_identifier(v)
-        return self.parse_constant(v)
+    def parse_array_const(self, tokens):
+        elems = []
+        while True:
+            token = tokens.pop()
+            if token.name == 'number':
+                elems.append(FloatConstant(token.v))
+            elif token.name == 'array_left':
+                elems.append(ArrayConstant(self.parse_array_const(tokens)))
+            else:
+                raise BadToken()
+            token = tokens.pop()
+            if token.name == 'array_right':
+                return elems
+            assert token.name == 'coma'
 
-    def parse_array_subscript(self, v):
-        v = v.strip(" ")
-        l = v.split("[")
-        lgt = len(l[1]) - 1
-        assert lgt >= 0
-        rhs = self.parse_constant_or_identifier(l[1][:lgt])
-        return l[0], rhs
-
-    def parse_statement(self, line):
-        if '=' in line:
-            lhs, rhs = line.split("=")
-            lhs = lhs.strip(" ")
-            if '[' in lhs:
-                name, index = self.parse_array_subscript(lhs)
-                return ArrayAssignment(name, index, self.parse_expression(rhs))
-            else:
-                return Assignment(lhs, self.parse_expression(rhs))
-        else:
-            return Execute(self.parse_expression(line))
+    def parse_statement(self, tokens):
+        if (tokens.get(0).name == 'identifier' and
+            tokens.get(1).name == 'assign'):
+            lhs = tokens.pop().v
+            tokens.pop()
+            rhs = self.parse_expression(tokens)
+            return Assignment(lhs, rhs)
+        elif (tokens.get(0).name == 'identifier' and
+              tokens.get(1).name == 'array_left'):
+            name = tokens.pop().v
+            tokens.pop()
+            index = self.parse_expression(tokens)
+            tokens.pop()
+            tokens.pop()
+            return ArrayAssignment(name, index, self.parse_expression(tokens))
+        return Execute(self.parse_expression(tokens))
 
     def parse(self, code):
         statements = []
@@ -447,7 +569,8 @@
                 line = line.split('#', 1)[0]
             line = line.strip(" ")
             if line:
-                statements.append(self.parse_statement(line))
+                tokens = self.tokenize(line)
+                statements.append(self.parse_statement(tokens))
         return Code(statements)
 
 def numpy_compile(code):
diff --git a/pypy/module/micronumpy/interp_numarray.py b/pypy/module/micronumpy/interp_numarray.py
--- a/pypy/module/micronumpy/interp_numarray.py
+++ b/pypy/module/micronumpy/interp_numarray.py
@@ -1,45 +1,347 @@
 from pypy.interpreter.baseobjspace import Wrappable
-from pypy.interpreter.error import OperationError
-from pypy.interpreter.gateway import interp2app, unwrap_spec
+from pypy.interpreter.error import OperationError, operationerrfmt
+from pypy.interpreter.gateway import interp2app, unwrap_spec, NoneNotWrapped
 from pypy.interpreter.typedef import TypeDef, GetSetProperty
 from pypy.module.micronumpy import interp_ufuncs, interp_dtype, signature
 from pypy.rlib import jit
 from pypy.rpython.lltypesystem import lltype
 from pypy.tool.sourcetools import func_with_new_name
+from pypy.rlib.rstring import StringBuilder
+from pypy.rlib.objectmodel import instantiate
 
 
-numpy_driver = jit.JitDriver(greens = ['signature'],
-                             reds = ['result_size', 'i', 'self', 'result'])
-all_driver = jit.JitDriver(greens=['signature'], reds=['i', 'size', 'self', 'dtype'])
-any_driver = jit.JitDriver(greens=['signature'], reds=['i', 'size', 'self', 'dtype'])
-slice_driver = jit.JitDriver(greens=['signature'], reds=['i', 'j', 'step', 'stop', 'source', 'dest'])
+numpy_driver = jit.JitDriver(
+    greens=['shapelen', 'signature'],
+    reds=['result_size', 'i', 'ri', 'self', 'result']
+)
+all_driver = jit.JitDriver(
+    greens=['shapelen', 'signature'],
+    reds=['i', 'self', 'dtype']
+)
+any_driver = jit.JitDriver(
+    greens=['shapelen', 'signature'],
+    reds=['i', 'self', 'dtype']
+)
+slice_driver = jit.JitDriver(
+    greens=['shapelen', 'signature'],
+    reds=['self', 'source', 'source_iter', 'res_iter']
+)
 
-def descr_new_array(space, w_subtype, w_size_or_iterable, w_dtype=None):
-    l = space.listview(w_size_or_iterable)
+def _find_shape_and_elems(space, w_iterable):
+    shape = [space.len_w(w_iterable)]
+    batch = space.listview(w_iterable)
+    while True:
+        new_batch = []
+        if not batch:
+            return shape, []
+        if not space.issequence_w(batch[0]):
+            for elem in batch:
+                if space.issequence_w(elem):
+                    raise OperationError(space.w_ValueError, space.wrap(
+                        "setting an array element with a sequence"))
+            return shape, batch
+        size = space.len_w(batch[0])
+        for w_elem in batch:
+            if not space.issequence_w(w_elem) or space.len_w(w_elem) != size:
+                raise OperationError(space.w_ValueError, space.wrap(
+                    "setting an array element with a sequence"))
+            new_batch += space.listview(w_elem)
+        shape.append(size)
+        batch = new_batch
+
+def shape_agreement(space, shape1, shape2):
+    ret = _shape_agreement(shape1, shape2)
+    if len(ret) < max(len(shape1), len(shape2)):
+        raise OperationError(space.w_ValueError,
+            space.wrap("operands could not be broadcast together with shapes (%s) (%s)" % (
+                ",".join([str(x) for x in shape1]),
+                ",".join([str(x) for x in shape2]),
+            ))
+        )
+    return ret
+
+def _shape_agreement(shape1, shape2):
+    """ Checks agreement about two shapes with respect to broadcasting. Returns
+    the resulting shape.
+    """
+    lshift = 0
+    rshift = 0
+    if len(shape1) > len(shape2):
+        m = len(shape1)
+        n = len(shape2)
+        rshift = len(shape2) - len(shape1)
+        remainder = shape1
+    else:
+        m = len(shape2)
+        n = len(shape1)
+        lshift = len(shape1) - len(shape2)
+        remainder = shape2
+    endshape = [0] * m
+    indices1 = [True] * m
+    indices2 = [True] * m
+    for i in range(m - 1, m - n - 1, -1):
+        left = shape1[i + lshift]
+        right = shape2[i + rshift]
+        if left == right:
+            endshape[i] = left
+        elif left == 1:
+            endshape[i] = right
+            indices1[i + lshift] = False
+        elif right == 1:
+            endshape[i] = left
+            indices2[i + rshift] = False
+        else:
+            return []
+            #raise OperationError(space.w_ValueError, space.wrap(
+            #    "frames are not aligned"))
+    for i in range(m - n):
+        endshape[i] = remainder[i]
+    return endshape
+
+def descr_new_array(space, w_subtype, w_item_or_iterable, w_dtype=None,
+                    w_order=NoneNotWrapped):
+    # find scalar
+    if not space.issequence_w(w_item_or_iterable):
+        w_dtype = interp_ufuncs.find_dtype_for_scalar(space,
+                                                      w_item_or_iterable,
+                                                      w_dtype)
+        dtype = space.interp_w(interp_dtype.W_Dtype,
+           space.call_function(space.gettypefor(interp_dtype.W_Dtype), w_dtype))
+        return scalar_w(space, dtype, w_item_or_iterable)
+    if w_order is None:
+        order = 'C'
+    else:
+        order = space.str_w(w_order)
+        if order != 'C':  # or order != 'F':
+            raise operationerrfmt(space.w_ValueError, "Unknown order: %s",
+                                  order)
+    shape, elems_w = _find_shape_and_elems(space, w_item_or_iterable)
+    # they come back in C order
+    size = len(elems_w)
     if space.is_w(w_dtype, space.w_None):
         w_dtype = None
-        for w_item in l:
-            w_dtype = interp_ufuncs.find_dtype_for_scalar(space, w_item, w_dtype)
+        for w_elem in elems_w:
+            w_dtype = interp_ufuncs.find_dtype_for_scalar(space, w_elem,
+                                                          w_dtype)
             if w_dtype is interp_dtype.get_dtype_cache(space).w_float64dtype:
                 break
-        if w_dtype is None:
-            w_dtype = space.w_None
-
+    if w_dtype is None:
+        w_dtype = space.w_None
     dtype = space.interp_w(interp_dtype.W_Dtype,
         space.call_function(space.gettypefor(interp_dtype.W_Dtype), w_dtype)
     )
-    arr = SingleDimArray(len(l), dtype=dtype)
-    i = 0
-    for w_elem in l:
-        dtype.setitem(arr.storage, i, dtype.coerce(space, w_elem))
-        i += 1
+    arr = NDimArray(size, shape[:], dtype=dtype, order=order)
+    shapelen = len(shape)
+    arr_iter = arr.start_iter(arr.shape)
+    for i in range(len(elems_w)):
+        w_elem = elems_w[i]
+        dtype.setitem(arr.storage, arr_iter.offset, dtype.coerce(space, w_elem))
+        arr_iter = arr_iter.next(shapelen)
     return arr
 
+# Iterators for arrays
+# --------------------
+# all those iterators with the exception of BroadcastIterator iterate over the
+# entire array in C order (the last index changes the fastest). This will
+# yield all elements. Views iterate over indices and look towards strides and
+# backstrides to find the correct position. Notably the offset between
+# x[..., i + 1] and x[..., i] will be strides[-1]. Offset between
+# x[..., k + 1, 0] and x[..., k, i_max] will be backstrides[-2] etc.
+
+# BroadcastIterator works like that, but for indexes that don't change source
+# in the original array, strides[i] == backstrides[i] == 0
+
+class BaseIterator(object):
+    def next(self, shapelen):
+        raise NotImplementedError
+
+    def done(self):
+        raise NotImplementedError
+
+    def get_offset(self):
+        raise NotImplementedError
+
+class ArrayIterator(BaseIterator):
+    def __init__(self, size):
+        self.offset = 0
+        self.size = size
+
+    def next(self, shapelen):
+        arr = instantiate(ArrayIterator)
+        arr.size = self.size
+        arr.offset = self.offset + 1
+        return arr
+
+    def done(self):
+        return self.offset >= self.size
+
+    def get_offset(self):
+        return self.offset
+
+class ViewIterator(BaseIterator):
+    def __init__(self, arr):
+        self.indices = [0] * len(arr.shape)
+        self.offset  = arr.start
+        self.arr     = arr
+        self._done   = False
+
+    @jit.unroll_safe
+    def next(self, shapelen):
+        offset = self.offset
+        indices = [0] * shapelen
+        for i in range(shapelen):
+            indices[i] = self.indices[i]
+        done = False
+        for i in range(shapelen - 1, -1, -1):
+            if indices[i] < self.arr.shape[i] - 1:
+                indices[i] += 1
+                offset += self.arr.strides[i]
+                break
+            else:
+                indices[i] = 0
+                offset -= self.arr.backstrides[i]
+        else:
+            done = True
+        res = instantiate(ViewIterator)
+        res.offset = offset
+        res.indices = indices
+        res.arr = self.arr
+        res._done = done
+        return res
+
+    def done(self):
+        return self._done
+
+    def get_offset(self):
+        return self.offset
+
+class BroadcastIterator(BaseIterator):
+    '''Like a view iterator, but will repeatedly access values
+       for all iterations across a res_shape, folding the offset
+       using mod() arithmetic
+    '''
+    def __init__(self, arr, res_shape):
+        self.indices = [0] * len(res_shape)
+        self.offset  = arr.start
+        #strides are 0 where original shape==1
+        self.strides = []
+        self.backstrides = []
+        for i in range(len(arr.shape)):
+            if arr.shape[i]==1:
+                self.strides.append(0)
+                self.backstrides.append(0)
+            else:
+                self.strides.append(arr.strides[i])
+                self.backstrides.append(arr.backstrides[i])
+        self.res_shape = res_shape
+        self.strides = [0] * (len(res_shape) - len(arr.shape)) + self.strides
+        self.backstrides = [0] * (len(res_shape) - len(arr.shape)) + self.backstrides
+        self._done = False
+
+    @jit.unroll_safe
+    def next(self, shapelen):
+        offset = self.offset
+        indices = [0] * shapelen
+        _done = False
+        for i in range(shapelen):
+            indices[i] = self.indices[i]
+        for i in range(shapelen - 1, -1, -1):
+            if indices[i] < self.res_shape[i] - 1:
+                indices[i] += 1
+                offset += self.strides[i]
+                break
+            else:
+                indices[i] = 0
+                offset -= self.backstrides[i]
+        else:
+            _done = True
+        res = instantiate(BroadcastIterator)
+        res.indices = indices
+        res.offset = offset
+        res._done = _done
+        res.strides = self.strides
+        res.backstrides = self.backstrides
+        res.res_shape = self.res_shape
+        return res
+
+    def done(self):
+        return self._done
+
+    def get_offset(self):
+        return self.offset
+
+class Call2Iterator(BaseIterator):
+    def __init__(self, left, right):
+        self.left = left
+        self.right = right
+
+    def next(self, shapelen):
+        return Call2Iterator(self.left.next(shapelen),
+                             self.right.next(shapelen))
+
+    def done(self):
+        if isinstance(self.left, ConstantIterator):
+            return self.right.done()
+        return self.left.done()
+
+    def get_offset(self):
+        if isinstance(self.left, ConstantIterator):
+            return self.right.get_offset()
+        return self.left.get_offset()
+
+class Call1Iterator(BaseIterator):
+    def __init__(self, child):
+        self.child = child
+
+    def next(self, shapelen):
+        return Call1Iterator(self.child.next(shapelen))
+
+    def done(self):
+        return self.child.done()
+
+    def get_offset(self):
+        return self.child.get_offset()
+
+class ConstantIterator(BaseIterator):
+    def next(self, shapelen):
+        return self
+
+    def done(self):
+        return False
+
+    def get_offset(self):
+        return 0
+
 class BaseArray(Wrappable):
-    _attrs_ = ["invalidates", "signature"]
+    _attrs_ = ["invalidates", "signature", "shape", "strides", "backstrides",
+               "start", 'order']
 
-    def __init__(self):
+    _immutable_fields_ = ['shape[*]', "strides[*]", "backstrides[*]", 'start',
+                          "order"]
+
+    strides = None
+    start = 0
+
+    def __init__(self, shape, order):
         self.invalidates = []
+        self.shape = shape
+        self.order = order
+        if self.strides is None:
+            strides = []
+            backstrides = []
+            s = 1
+            shape_rev = shape[:]
+            if order == 'C':
+                shape_rev.reverse()
+            for sh in shape_rev:
+                strides.append(s)
+                backstrides.append(s * (sh - 1))
+                s *= sh
+            if order == 'C':
+                strides.reverse()
+                backstrides.reverse()
+            self.strides = strides[:]
+            self.backstrides = backstrides[:]
 
     def invalidated(self):
         if self.invalidates:
@@ -99,7 +401,7 @@
 
     def _reduce_ufunc_impl(ufunc_name):
         def impl(self, space):
-            return getattr(interp_ufuncs.get(space), ufunc_name).descr_reduce(space, self)
+            return getattr(interp_ufuncs.get(space), ufunc_name).reduce(space, self, multidim=True)
         return func_with_new_name(impl, "reduce_%s_impl" % ufunc_name)
 
     descr_sum = _reduce_ufunc_impl("add")
@@ -108,55 +410,65 @@
     descr_min = _reduce_ufunc_impl("minimum")
 
     def _reduce_argmax_argmin_impl(op_name):
-        reduce_driver = jit.JitDriver(greens=['signature'],
-                         reds = ['i', 'size', 'result', 'self', 'cur_best', 'dtype'])
-        def loop(self, size):
+        reduce_driver = jit.JitDriver(
+            greens=['shapelen', 'signature'],
+            reds=['result', 'idx', 'i', 'self', 'cur_best', 'dtype']
+        )
+        def loop(self):
+            i = self.start_iter()
+            cur_best = self.eval(i)
+            shapelen = len(self.shape)
+            i = i.next(shapelen)
+            dtype = self.find_dtype()
             result = 0
-            cur_best = self.eval(0)
-            i = 1
-            dtype = self.find_dtype()
-            while i < size:
+            idx = 1
+            while not i.done():
                 reduce_driver.jit_merge_point(signature=self.signature,
+                                              shapelen=shapelen,
                                               self=self, dtype=dtype,
-                                              size=size, i=i, result=result,
+                                              i=i, result=result, idx=idx,
                                               cur_best=cur_best)
                 new_best = getattr(dtype.itemtype, op_name)(cur_best, self.eval(i))
                 if dtype.itemtype.ne(new_best, cur_best):
-                    result = i
+                    result = idx
                     cur_best = new_best
-                i += 1
+                i = i.next(shapelen)
+                idx += 1
             return result
         def impl(self, space):
             size = self.find_size()
             if size == 0:
                 raise OperationError(space.w_ValueError,
-                    space.wrap("Can't call %s on zero-size arrays" \
-                            % op_name))
-            return space.wrap(loop(self, size))
+                    space.wrap("Can't call %s on zero-size arrays" % op_name))
+            return space.wrap(loop(self))
         return func_with_new_name(impl, "reduce_arg%s_impl" % op_name)
 
     def _all(self):
-        size = self.find_size()
         dtype = self.find_dtype()
-        i = 0
-        while i < size:
-            all_driver.jit_merge_point(signature=self.signature, self=self, dtype=dtype, size=size, i=i)
+        i = self.start_iter()
+        shapelen = len(self.shape)
+        while not i.done():
+            all_driver.jit_merge_point(signature=self.signature,
+                                       shapelen=shapelen, self=self,
+                                       dtype=dtype, i=i)
             if not dtype.itemtype.bool(self.eval(i)):
                 return False
-            i += 1
+            i = i.next(shapelen)
         return True
     def descr_all(self, space):
         return space.wrap(self._all())
 
     def _any(self):
-        size = self.find_size()
         dtype = self.find_dtype()
-        i = 0
-        while i < size:
-            any_driver.jit_merge_point(signature=self.signature, self=self, size=size, dtype=dtype, i=i)
+        i = self.start_iter()
+        shapelen = len(self.shape)
+        while not i.done():
+            any_driver.jit_merge_point(signature=self.signature,
+                                       shapelen=shapelen, self=self,
+                                       dtype=dtype, i=i)
             if dtype.itemtype.bool(self.eval(i)):
                 return True
-            i += 1
+            i = i.next(shapelen)
         return False
     def descr_any(self, space):
         return space.wrap(self._any())
@@ -173,25 +485,6 @@
             assert isinstance(w_res, BaseArray)
             return w_res.descr_sum(space)
 
-    def _getnums(self, comma):
-        dtype = self.find_dtype()
-        if self.find_size() > 1000:
-            nums = [
-                dtype.itemtype.str_format(self.eval(index))
-                for index in range(3)
-            ]
-            nums.append("..." + "," * comma)
-            nums.extend([
-                dtype.itemtype.str_format(self.eval(index))
-                for index in range(self.find_size() - 3, self.find_size())
-            ])
-        else:
-            nums = [
-                dtype.itemtype.str_format(self.eval(index))
-                for index in range(self.find_size())
-            ]
-        return nums
-
     def get_concrete(self):
         raise NotImplementedError
 
@@ -199,7 +492,7 @@
         return space.wrap(self.find_dtype())
 
     def descr_get_shape(self, space):
-        return space.newtuple([self.descr_len(space)])
+        return space.newtuple([space.wrap(i) for i in self.shape])
 
     def descr_get_size(self, space):
         return space.wrap(self.find_size())
@@ -211,89 +504,264 @@
         return self.get_concrete().descr_len(space)
 
     def descr_repr(self, space):
-        # Simple implementation so that we can see the array. Needs work.
+        res = StringBuilder()
+        res.append("array(")
         concrete = self.get_concrete()
-        res = "array([" + ", ".join(concrete._getnums(False)) + "]"
         dtype = concrete.find_dtype()
+        if not concrete.find_size():
+            res.append('[]')
+            if len(self.shape) > 1:
+                # An empty slice reports its shape
+                res.append(", shape=(")
+                self_shape = str(self.shape)
+                res.append_slice(str(self_shape), 1, len(self_shape) - 1)
+                res.append(')')
+        else:
+            concrete.to_str(space, 1, res, indent='       ')
         if (dtype is not interp_dtype.get_dtype_cache(space).w_float64dtype and
-            dtype is not interp_dtype.get_dtype_cache(space).w_int64dtype) or not self.find_size():
-            res += ", dtype=" + dtype.name
-        res += ")"
-        return space.wrap(res)
+            dtype is not interp_dtype.get_dtype_cache(space).w_int64dtype) or \
+            not self.find_size():
+            res.append(", dtype=" + dtype.name)
+        res.append(")")
+        return space.wrap(res.build())
+
+    def to_str(self, space, comma, builder, indent=' ', use_ellipsis=False):
+        '''Modifies builder with a representation of the array/slice
+        The items will be seperated by a comma if comma is 1
+        Multidimensional arrays/slices will span a number of lines,
+        each line will begin with indent.
+        '''
+        size = self.find_size()
+        if size < 1:
+            builder.append('[]')
+            return
+        if size > 1000:
+            # Once this goes True it does not go back to False for recursive
+            # calls
+            use_ellipsis = True
+        dtype = self.find_dtype()
+        ndims = len(self.shape)
+        i = 0
+        start = True
+        builder.append('[')
+        if ndims > 1:
+            if use_ellipsis:
+                for i in range(3):
+                    if start:
+                        start = False
+                    else:
+                        builder.append(',' * comma + '\n')
+                        if ndims == 3:
+                            builder.append('\n' + indent)
+                        else:
+                            builder.append(indent)
+                    # create_slice requires len(chunks) > 1 in order to reduce
+                    # shape
+                    view = self.create_slice(space, [(i, 0, 0, 1), (0, self.shape[1], 1, self.shape[1])])
+                    view.to_str(space, comma, builder, indent=indent + ' ', use_ellipsis=use_ellipsis)
+                builder.append('\n' + indent + '..., ')
+                i = self.shape[0] - 3
+            while i < self.shape[0]:
+                if start:
+                    start = False
+                else:
+                    builder.append(',' * comma + '\n')
+                    if ndims == 3:
+                        builder.append('\n' + indent)
+                    else:
+                        builder.append(indent)
+                # create_slice requires len(chunks) > 1 in order to reduce
+                # shape
+                view = self.create_slice(space, [(i, 0, 0, 1), (0, self.shape[1], 1, self.shape[1])])
+                view.to_str(space, comma, builder, indent=indent + ' ', use_ellipsis=use_ellipsis)
+                i += 1
+        elif ndims == 1:
+            spacer = ',' * comma + ' '
+            item = self.start
+            # An iterator would be a nicer way to walk along the 1d array, but
+            # how do I reset it if printing ellipsis? iterators have no
+            # "set_offset()"
+            i = 0
+            if use_ellipsis:
+                for i in range(3):
+                    if start:
+                        start = False
+                    else:
+                        builder.append(spacer)
+                    builder.append(dtype.itemtype.str_format(self.getitem(item)))
+                    item += self.strides[0]
+                # Add a comma only if comma is False - this prevents adding two
+                # commas
+                builder.append(spacer + '...' + ',' * (1 - comma))
+                # Ugly, but can this be done with an iterator?
+                item = self.start + self.backstrides[0] - 2 * self.strides[0]
+                i = self.shape[0] - 3
+            while i < self.shape[0]:
+                if start:
+                    start = False
+                else:
+                    builder.append(spacer)
+                builder.append(dtype.itemtype.str_format(self.getitem(item)))
+                item += self.strides[0]
+                i += 1
+        else:
+            builder.append('[')
+        builder.append(']')
 
     def descr_str(self, space):
-        # Simple implementation so that we can see the array. Needs work.
+        ret = StringBuilder()
         concrete = self.get_concrete()
-        return space.wrap("[" + " ".join(concrete._getnums(True)) + "]")
+        concrete.to_str(space, 0, ret, ' ')
+        return space.wrap(ret.build())
+
+    def _index_of_single_item(self, space, w_idx):
+        if space.isinstance_w(w_idx, space.w_int):
+            idx = space.int_w(w_idx)
+            if not self.shape:
+                if idx != 0:
+                    raise OperationError(space.w_IndexError,
+                                         space.wrap("index out of range"))
+                return 0
+            if idx < 0:
+                idx = self.shape[0] + idx
+            if idx < 0 or idx >= self.shape[0]:
+                raise OperationError(space.w_IndexError,
+                                     space.wrap("index out of range"))
+            return self.start + idx * self.strides[0]
+        index = [space.int_w(w_item)
+                 for w_item in space.fixedview(w_idx)]
+        item = self.start
+        for i in range(len(index)):
+            v = index[i]
+            if v < 0:
+                v += self.shape[i]
+            if v < 0 or v >= self.shape[i]:
+                raise operationerrfmt(space.w_IndexError,
+                    "index (%d) out of range (0<=index<%d", i, self.shape[i],
+                )
+            item += v * self.strides[i]
+        return item
+
+    def _single_item_result(self, space, w_idx):
+        """ The result of getitem/setitem is a single item if w_idx
+        is a list of scalars that match the size of shape
+        """
+        shape_len = len(self.shape)
+        if shape_len == 0:
+            if not space.isinstance_w(w_idx, space.w_int):
+                raise OperationError(space.w_IndexError, space.wrap(
+                    "wrong index"))
+            return True
+        if shape_len == 1:
+            if space.isinstance_w(w_idx, space.w_int):
+                return True
+            if space.isinstance_w(w_idx, space.w_slice):
+                return False
+        elif (space.isinstance_w(w_idx, space.w_slice) or
+              space.isinstance_w(w_idx, space.w_int)):
+            return False
+        lgt = space.len_w(w_idx)
+        if lgt > shape_len:
+            raise OperationError(space.w_IndexError,
+                                 space.wrap("invalid index"))
+        if lgt < shape_len:
+            return False
+        for w_item in space.fixedview(w_idx):
+            if space.isinstance_w(w_item, space.w_slice):
+                return False
+        return True
+
+    def _prepare_slice_args(self, space, w_idx):
+        if (space.isinstance_w(w_idx, space.w_int) or
+            space.isinstance_w(w_idx, space.w_slice)):
+            return [space.decode_index4(w_idx, self.shape[0])]
+        return [space.decode_index4(w_item, self.shape[i]) for i, w_item in
+                enumerate(space.fixedview(w_idx))]
 
     def descr_getitem(self, space, w_idx):
-        # TODO: indexing by arrays and lists
-        if space.isinstance_w(w_idx, space.w_tuple):
-            length = space.len_w(w_idx)
-            if length == 0:
-                return space.wrap(self)
-            if length > 1: # only one dimension for now.
-                raise OperationError(space.w_IndexError,
-                                     space.wrap("invalid index"))
-            w_idx = space.getitem(w_idx, space.wrap(0))
-        start, stop, step, slice_length = space.decode_index4(w_idx, self.find_size())
-        if step == 0:
-            # Single index
-            return self.get_concrete().eval(start)
-        else:
-            # Slice
-            new_sig = signature.Signature.find_sig([
-                SingleDimSlice.signature, self.signature
-            ])
-            res = SingleDimSlice(start, stop, step, slice_length, self, new_sig)
-            return space.wrap(res)
+        if self._single_item_result(space, w_idx):
+            concrete = self.get_concrete()
+            item = concrete._index_of_single_item(space, w_idx)
+            return concrete.getitem(item)
+        chunks = self._prepare_slice_args(space, w_idx)
+        return space.wrap(self.create_slice(space, chunks))
 
     def descr_setitem(self, space, w_idx, w_value):
-        # TODO: indexing by arrays and lists
         self.invalidated()
-        if space.isinstance_w(w_idx, space.w_tuple):
-            length = space.len_w(w_idx)
-            if length > 1: # only one dimension for now.
-                raise OperationError(space.w_IndexError,
-                                     space.wrap("invalid index"))
-            if length == 0:
-                w_idx = space.newslice(space.wrap(0),
-                                      space.wrap(self.find_size()),
-                                      space.wrap(1))
+        concrete = self.get_concrete()
+        if self._single_item_result(space, w_idx):
+            item = concrete._index_of_single_item(space, w_idx)
+            concrete.setitem_w(space, item, w_value)
+            return
+        if isinstance(w_value, BaseArray):
+            # for now we just copy if setting part of an array from
+            # part of itself. can be improved.
+            if (concrete.get_root_storage() ==
+                w_value.get_concrete().get_root_storage()):
+                w_value = space.call_function(space.gettypefor(BaseArray), w_value)
+                assert isinstance(w_value, BaseArray)
+        else:
+            w_value = convert_to_array(space, w_value)
+        chunks = self._prepare_slice_args(space, w_idx)
+        view = self.create_slice(space, chunks)
+        view.setslice(space, w_value)
+
+    def create_slice(self, space, chunks):
+        if len(chunks) == 1:
+            start, stop, step, lgt = chunks[0]
+            if step == 0:
+                shape = self.shape[1:]
+                strides = self.strides[1:]
+                backstrides = self.backstrides[1:]
             else:
-                w_idx = space.getitem(w_idx, space.wrap(0))
-        start, stop, step, slice_length = space.decode_index4(w_idx,
-                                                              self.find_size())
-        if step == 0:
-            # Single index
-            self.get_concrete().setitem_w(space, start, w_value)
+                shape = [lgt] + self.shape[1:]
+                strides = [self.strides[0] * step] + self.strides[1:]
+                backstrides = [(lgt - 1) * self.strides[0] * step] + self.backstrides[1:]
+            start *= self.strides[0]
+            start += self.start
         else:
-            concrete = self.get_concrete()
-            if isinstance(w_value, BaseArray):
-                # for now we just copy if setting part of an array from
-                # part of itself. can be improved.
-                if (concrete.get_root_storage() ==
-                    w_value.get_concrete().get_root_storage()):
-                    w_value = space.call_function(space.gettypefor(BaseArray), w_value)
-                    assert isinstance(w_value, BaseArray)
-            else:
-                w_value = convert_to_array(space, w_value)
-            concrete.setslice(space, start, stop, step,
-                                               slice_length, w_value)
+            shape = []
+            strides = []
+            backstrides = []
+            start = self.start
+            i = -1
+            for i, (start_, stop, step, lgt) in enumerate(chunks):
+                if step != 0:
+                    shape.append(lgt)
+                    strides.append(self.strides[i] * step)
+                    backstrides.append(self.strides[i] * (lgt - 1) * step)
+                start += self.strides[i] * start_
+            # add a reminder
+            s = i + 1
+            assert s >= 0
+            shape += self.shape[s:]
+            strides += self.strides[s:]
+            backstrides += self.backstrides[s:]
+        new_sig = signature.Signature.find_sig([
+            NDimSlice.signature, self.signature,
+        ])
+        return NDimSlice(self, new_sig, start, strides[:], backstrides[:],
+                         shape[:])
 
     def descr_mean(self, space):
         return space.div(self.descr_sum(space), space.wrap(self.find_size()))
 
-    def _sliceloop(self, start, stop, step, source, dest):
-        i = start
-        j = 0
-        while (step > 0 and i < stop) or (step < 0 and i > stop):
-            slice_driver.jit_merge_point(signature=source.signature, step=step,
-                                         stop=stop, i=i, j=j, source=source,
-                                         dest=dest)
-            dest.setitem(i, source.eval(j).convert_to(dest.find_dtype()))
-            j += 1
-            i += step
+    def descr_nonzero(self, space):
+        try:
+            if self.find_size() > 1:
+                raise OperationError(space.w_ValueError, space.wrap(
+                    "The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()"))
+        except ValueError:
+            pass
+        return space.wrap(space.is_true(
+            self.get_concrete().eval(self.start_iter(self.shape))
+        ))
+
+    def getitem(self, item):
+        raise NotImplementedError
+
+    def start_iter(self, res_shape=None):
+        raise NotImplementedError
 
 def convert_to_array(space, w_obj):
     if isinstance(w_obj, BaseArray):
@@ -313,32 +781,44 @@
 
 class Scalar(BaseArray):
     """
-    Intermediate class representing a float literal.
+    Intermediate class representing a literal.
     """
     signature = signature.BaseSignature()
 
-    _attrs_ = ["dtype", "value"]
+    _attrs_ = ["dtype", "value", "shape"]
 
     def __init__(self, dtype, value):
-        BaseArray.__init__(self)
+        BaseArray.__init__(self, [], 'C')
         self.dtype = dtype
         self.value = value
 
     def find_size(self):
         raise ValueError
 
+    def get_concrete(self):
+        return self
+
     def find_dtype(self):
         return self.dtype
 
-    def eval(self, i):
+    def getitem(self, item):
         return self.value
 
+    def eval(self, iter):
+        return self.value
+
+    def start_iter(self, res_shape=None):
+        return ConstantIterator()
+
+    def to_str(self, space, comma, builder, indent=' ', use_ellipsis=False):
+        builder.append(self.dtype.itemtype.str_format(self.value))
+
 class VirtualArray(BaseArray):
     """
     Class for representing virtual arrays, such as binary ops or ufuncs
     """
-    def __init__(self, signature, res_dtype):
-        BaseArray.__init__(self)
+    def __init__(self, signature, shape, res_dtype, order):
+        BaseArray.__init__(self, shape, order)
         self.forced_result = None
         self.signature = signature
         self.res_dtype = res_dtype
@@ -351,13 +831,18 @@
         i = 0
         signature = self.signature
         result_size = self.find_size()
-        result = SingleDimArray(result_size, self.find_dtype())
-        while i < result_size:
+        result = NDimArray(result_size, self.shape, self.find_dtype())
+        shapelen = len(self.shape)
+        i = self.start_iter()
+        ri = result.start_iter()
+        while not ri.done():
             numpy_driver.jit_merge_point(signature=signature,
-                                         result_size=result_size, i=i,
+                                         shapelen=shapelen,
+                                         result_size=result_size, i=i, ri=ri,
                                          self=self, result=result)
-            result.dtype.setitem(result.storage, i, self.eval(i))
-            i += 1
+            result.dtype.setitem(result.storage, ri.offset, self.eval(i))
+            i = i.next(shapelen)
+            ri = ri.next(shapelen)
         return result
 
     def force_if_needed(self):
@@ -369,10 +854,13 @@
         self.force_if_needed()
         return self.forced_result
 
-    def eval(self, i):
+    def eval(self, iter):
         if self.forced_result is not None:
-            return self.forced_result.eval(i)
-        return self._eval(i)
+            return self.forced_result.eval(iter)
+        return self._eval(iter)
+
+    def getitem(self, item):
+        return self.get_concrete().getitem(item)
 
     def setitem(self, item, value):
         return self.get_concrete().setitem(item, value)
@@ -388,8 +876,9 @@
 
 
 class Call1(VirtualArray):
-    def __init__(self, signature, res_dtype, values):
-        VirtualArray.__init__(self, signature, res_dtype)
+    def __init__(self, signature, shape, res_dtype, values, order):
+        VirtualArray.__init__(self, signature, shape, res_dtype,
+                              values.order)
         self.values = values
 
     def _del_sources(self):
@@ -401,40 +890,53 @@
     def _find_dtype(self):
         return self.res_dtype
 
-    def _eval(self, i):
-        val = self.values.eval(i).convert_to(self.res_dtype)
-
+    def _eval(self, iter):
+        assert isinstance(iter, Call1Iterator)
+        val = self.values.eval(iter.child).convert_to(self.res_dtype)
         sig = jit.promote(self.signature)
         assert isinstance(sig, signature.Signature)
         call_sig = sig.components[0]
         assert isinstance(call_sig, signature.Call1)
         return call_sig.func(self.res_dtype, val)
 
+    def start_iter(self, res_shape=None):
+        if self.forced_result is not None:
+            return self.forced_result.start_iter(res_shape)
+        return Call1Iterator(self.values.start_iter(res_shape))
+
 class Call2(VirtualArray):
     """
     Intermediate class for performing binary operations.
     """
-    def __init__(self, signature, calc_dtype, res_dtype, left, right):
-        VirtualArray.__init__(self, signature, res_dtype)
+    def __init__(self, signature, shape, calc_dtype, res_dtype, left, right):
+        # XXX do something if left.order != right.order
+        VirtualArray.__init__(self, signature, shape, res_dtype, left.order)
         self.left = left
         self.right = right
         self.calc_dtype = calc_dtype
+        self.size = 1
+        for s in self.shape:
+            self.size *= s
 
     def _del_sources(self):
         self.left = None
         self.right = None
 
     def _find_size(self):
-        try:
-            return self.left.find_size()
-        except ValueError:
-            pass
-        return self.right.find_size()
+        return self.size
 
-    def _eval(self, i):
-        lhs = self.left.eval(i).convert_to(self.calc_dtype)
-        rhs = self.right.eval(i).convert_to(self.calc_dtype)
+    def start_iter(self, res_shape=None):
+        if self.forced_result is not None:
+            return self.forced_result.start_iter(res_shape)
+        if res_shape is None:
+            res_shape = self.shape  # we still force the shape on children
+        return Call2Iterator(self.left.start_iter(res_shape),
+                             self.right.start_iter(res_shape))
 
+    def _eval(self, iter):
+        assert isinstance(iter, Call2Iterator)
+        lhs = self.left.eval(iter.left).convert_to(self.calc_dtype)
+        rhs = self.right.eval(iter.right).convert_to(self.calc_dtype)
         sig = jit.promote(self.signature)
         assert isinstance(sig, signature.Signature)
         call_sig = sig.components[0]
@@ -446,8 +948,10 @@
     Class for representing views of arrays, they will reflect changes of parent
     arrays. Example: slices
     """
-    def __init__(self, parent, signature):
-        BaseArray.__init__(self)
+    def __init__(self, parent, signature, strides, backstrides, shape):
+        self.strides = strides
+        self.backstrides = backstrides
+        BaseArray.__init__(self, shape, parent.order)
         self.signature = signature
         self.parent = parent
         self.invalidates = parent.invalidates
@@ -459,39 +963,40 @@
         self.parent.get_concrete()
         return self
 
-    def eval(self, i):
-        return self.parent.eval(self.calc_index(i))
+    def getitem(self, item):
+        return self.parent.getitem(item)
+
+    def eval(self, iter):
+        return self.parent.getitem(iter.get_offset())
 
     @unwrap_spec(item=int)
     def setitem_w(self, space, item, w_value):
-        return self.parent.setitem_w(space, self.calc_index(item), w_value)
+        return self.parent.setitem_w(space, item, w_value)
 
     def setitem(self, item, value):
         # This is currently not possible to be called from anywhere.
         raise NotImplementedError
 
     def descr_len(self, space):
-        return space.wrap(self.find_size())
+        if self.shape:
+            return space.wrap(self.shape[0])
+        return space.wrap(1)
 
-    def calc_index(self, item):
-        raise NotImplementedError
+class VirtualView(VirtualArray):
+    pass
 
-class SingleDimSlice(ViewArray):
+class NDimSlice(ViewArray):
     signature = signature.BaseSignature()
 
-    def __init__(self, start, stop, step, slice_length, parent, signature):
-        ViewArray.__init__(self, parent, signature)
-        if isinstance(parent, SingleDimSlice):
-            self.start = parent.calc_index(start)
-            self.stop = parent.calc_index(stop)
-            self.step = parent.step * step
-            self.parent = parent.parent
-        else:
-            self.start = start
-            self.stop = stop
-            self.step = step
-            self.parent = parent
-        self.size = slice_length
+    def __init__(self, parent, signature, start, strides, backstrides,
+                 shape):
+        if isinstance(parent, NDimSlice):
+            parent = parent.parent
+        ViewArray.__init__(self, parent, signature, strides, backstrides, shape)
+        self.start = start
+        self.size = 1
+        for sh in shape:
+            self.size *= sh
 
     def get_root_storage(self):
         return self.parent.get_concrete().get_root_storage()
@@ -502,20 +1007,41 @@
     def find_dtype(self):
         return self.parent.find_dtype()
 
-    def setslice(self, space, start, stop, step, slice_length, arr):
-        start = self.calc_index(start)
-        if stop != -1:
-            stop = self.calc_index(stop)
-        step = self.step * step
-        self._sliceloop(start, stop, step, arr, self.parent)
+    def setslice(self, space, w_value):
+        res_shape = shape_agreement(space, self.shape, w_value.shape)
+        self._sliceloop(w_value, res_shape)
 
-    def calc_index(self, item):
-        return (self.start + item * self.step)
+    def _sliceloop(self, source, res_shape):
+        source_iter = source.start_iter(res_shape)
+        res_iter = self.start_iter(res_shape)
+        shapelen = len(res_shape)
+        while not res_iter.done():
+            slice_driver.jit_merge_point(signature=source.signature,
+                                         shapelen=shapelen,
+                                         self=self, source=source,
+                                         res_iter=res_iter,
+                                         source_iter=source_iter)
+            self.setitem(res_iter.offset, source.eval(source_iter).convert_to(
+                self.find_dtype()))
+            source_iter = source_iter.next(shapelen)
+            res_iter = res_iter.next(shapelen)
 
+    def start_iter(self, res_shape=None):
+        if res_shape is not None and res_shape != self.shape:
+            return BroadcastIterator(self, res_shape)
+        # XXX there is a possible optimization here with SingleDimViewIterator
+        #     ignore for now
+        return ViewIterator(self)
 
-class SingleDimArray(BaseArray):
-    def __init__(self, size, dtype):
-        BaseArray.__init__(self)
+    def setitem(self, item, value):
+        self.parent.setitem(item, value)
+
+class NDimArray(BaseArray):
+    """ A class representing contiguous array. We know that each iteration
+    by say ufunc will increase the data index by one
+    """
+    def __init__(self, size, shape, dtype, order='C'):
+        BaseArray.__init__(self, shape, order)
         self.size = size
         self.dtype = dtype
         self.storage = dtype.malloc(size)
@@ -533,11 +1059,17 @@
     def find_dtype(self):
         return self.dtype
 
-    def eval(self, i):
-        return self.dtype.getitem(self.storage, i)
+    def getitem(self, item):
+        return self.dtype.getitem(self.storage, item)
+
+    def eval(self, iter):
+        return self.dtype.getitem(self.storage, iter.get_offset())
 
     def descr_len(self, space):
-        return space.wrap(self.size)
+        if len(self.shape):
+            return space.wrap(self.shape[0])
+        raise OperationError(space.w_TypeError, space.wrap(
+            "len() of unsized object"))
 
     def setitem_w(self, space, item, w_value):
         return self.setitem(item, self.dtype.coerce(space, w_value))
@@ -546,26 +1078,43 @@
         self.invalidated()
         self.dtype.setitem(self.storage, item, value)
 
-    def setslice(self, space, start, stop, step, slice_length, arr):
-        self._sliceloop(start, stop, step, arr, self)
+    def start_iter(self, res_shape=None):
+        if self.order == 'C':
+            if res_shape is not None and res_shape != self.shape:
+                return BroadcastIterator(self, res_shape)
+            return ArrayIterator(self.size)
+        raise NotImplementedError  # use ViewIterator simply, test it
 
     def __del__(self):
         lltype.free(self.storage, flavor='raw', track_allocation=False)
 
- at unwrap_spec(size=int)
-def zeros(space, size, w_dtype=None):
+def _find_size_and_shape(space, w_size):
+    if space.isinstance_w(w_size, space.w_int):
+        size = space.int_w(w_size)
+        shape = [size]
+    else:
+        size = 1
+        shape = []
+        for w_item in space.fixedview(w_size):
+            item = space.int_w(w_item)
+            size *= item
+            shape.append(item)
+    return size, shape
+
+def zeros(space, w_size, w_dtype=None):
     dtype = space.interp_w(interp_dtype.W_Dtype,
         space.call_function(space.gettypefor(interp_dtype.W_Dtype), w_dtype)
     )
-    return space.wrap(SingleDimArray(size, dtype=dtype))
+    size, shape = _find_size_and_shape(space, w_size)
+    return space.wrap(NDimArray(size, shape[:], dtype=dtype))
 
- at unwrap_spec(size=int)
-def ones(space, size, w_dtype=None):
+def ones(space, w_size, w_dtype=None):
     dtype = space.interp_w(interp_dtype.W_Dtype,
         space.call_function(space.gettypefor(interp_dtype.W_Dtype), w_dtype)
     )
 
-    arr = SingleDimArray(size, dtype=dtype)
+    size, shape = _find_size_and_shape(space, w_size)
+    arr = NDimArray(size, shape[:], dtype=dtype)
     one = dtype.box(1)
     arr.dtype.fill(arr.storage, one, 0, size)
     return space.wrap(arr)
@@ -582,6 +1131,7 @@
     __pos__ = interp2app(BaseArray.descr_pos),
     __neg__ = interp2app(BaseArray.descr_neg),
     __abs__ = interp2app(BaseArray.descr_abs),
+    __nonzero__ = interp2app(BaseArray.descr_nonzero),
 
     __add__ = interp2app(BaseArray.descr_add),
     __sub__ = interp2app(BaseArray.descr_sub),
diff --git a/pypy/module/micronumpy/interp_support.py b/pypy/module/micronumpy/interp_support.py
--- a/pypy/module/micronumpy/interp_support.py
+++ b/pypy/module/micronumpy/interp_support.py
@@ -9,7 +9,7 @@
 
 @unwrap_spec(s=str)
 def fromstring(space, s):
-    from pypy.module.micronumpy.interp_numarray import SingleDimArray
+    from pypy.module.micronumpy.interp_numarray import NDimArray
     length = len(s)
 
     if length % FLOAT_SIZE == 0:
@@ -19,7 +19,7 @@
             "string length %d not divisable by %d" % (length, FLOAT_SIZE)))
 
     dtype = get_dtype_cache(space).w_float64dtype
-    a = SingleDimArray(number, dtype=dtype)
+    a = NDimArray(number, [number], dtype=dtype)
 
     start = 0
     end = FLOAT_SIZE
@@ -31,4 +31,4 @@
         start += FLOAT_SIZE
         end += FLOAT_SIZE
 
-    return space.wrap(a)
\ No newline at end of file
+    return space.wrap(a)
diff --git a/pypy/module/micronumpy/interp_ufuncs.py b/pypy/module/micronumpy/interp_ufuncs.py
--- a/pypy/module/micronumpy/interp_ufuncs.py
+++ b/pypy/module/micronumpy/interp_ufuncs.py
@@ -1,6 +1,6 @@
 from pypy.interpreter.baseobjspace import Wrappable
 from pypy.interpreter.error import OperationError, operationerrfmt
-from pypy.interpreter.gateway import interp2app
+from pypy.interpreter.gateway import interp2app, unwrap_spec
 from pypy.interpreter.typedef import TypeDef, GetSetProperty, interp_attrproperty
 from pypy.module.micronumpy import interp_boxes, interp_dtype, signature, types
 from pypy.rlib import jit
@@ -9,8 +9,8 @@
 
 
 reduce_driver = jit.JitDriver(
-    greens = ["signature"],
-    reds = ["i", "size", "self", "dtype", "value", "obj"]
+    greens = ['shapelen', "signature"],
+    reds = ["i", "self", "dtype", "value", "obj"]
 )
 
 class W_Ufunc(Wrappable):
@@ -45,8 +45,10 @@
         return self.call(space, __args__.arguments_w)
 
     def descr_reduce(self, space, w_obj):
+        return self.reduce(space, w_obj, multidim=False)
+
+    def reduce(self, space, w_obj, multidim):
         from pypy.module.micronumpy.interp_numarray import convert_to_array, Scalar
-
         if self.argcount != 2:
             raise OperationError(space.w_ValueError, space.wrap("reduce only "
                 "supported for binary functions"))
@@ -62,28 +64,32 @@
             space, obj.find_dtype(),
             promote_to_largest=True
         )
-        start = 0
+        start = obj.start_iter(obj.shape)
+        shapelen = len(obj.shape)
+        if shapelen > 1 and not multidim:
+            raise OperationError(space.w_NotImplementedError,
+                space.wrap("not implemented yet"))
         if self.identity is None:
             if size == 0:
                 raise operationerrfmt(space.w_ValueError, "zero-size array to "
                     "%s.reduce without identity", self.name)
-            value = obj.eval(0).convert_to(dtype)
-            start += 1
+            value = obj.eval(start).convert_to(dtype)
+            start = start.next(shapelen)
         else:
             value = self.identity.convert_to(dtype)
         new_sig = signature.Signature.find_sig([
             self.reduce_signature, obj.signature
         ])
-        return self.reduce(new_sig, start, value, obj, dtype, size)
+        return self.reduce_loop(new_sig, shapelen, start, value, obj, dtype)
 
-    def reduce(self, signature, start, value, obj, dtype, size):
-        i = start
-        while i < size:
-            reduce_driver.jit_merge_point(signature=signature, self=self,
+    def reduce_loop(self, signature, shapelen, i, value, obj, dtype):
+        while not i.done():
+            reduce_driver.jit_merge_point(signature=signature,
+                                          shapelen=shapelen, self=self,
                                           value=value, obj=obj, i=i,
-                                          dtype=dtype, size=size)
+                                          dtype=dtype)
             value = self.func(dtype, value, obj.eval(i).convert_to(dtype))
-            i += 1
+            i = i.next(shapelen)
         return value
 
 class W_Ufunc1(W_Ufunc):
@@ -111,7 +117,7 @@
             return self.func(res_dtype, w_obj.value.convert_to(res_dtype))
 
         new_sig = signature.Signature.find_sig([self.signature, w_obj.signature])
-        w_res = Call1(new_sig, res_dtype, w_obj)
+        w_res = Call1(new_sig, w_obj.shape, res_dtype, w_obj, w_obj.order)
         w_obj.add_invalidates(w_res)
         return w_res
 
@@ -130,7 +136,7 @@
 
     def call(self, space, args_w):
         from pypy.module.micronumpy.interp_numarray import (Call2,
-            convert_to_array, Scalar)
+            convert_to_array, Scalar, shape_agreement)
 
         [w_lhs, w_rhs] = args_w
         w_lhs = convert_to_array(space, w_lhs)
@@ -153,7 +159,9 @@
         new_sig = signature.Signature.find_sig([
             self.signature, w_lhs.signature, w_rhs.signature
         ])
-        w_res = Call2(new_sig, calc_dtype, res_dtype, w_lhs, w_rhs)
+        new_shape = shape_agreement(space, w_lhs.shape, w_rhs.shape)
+        w_res = Call2(new_sig, new_shape, calc_dtype,
+                      res_dtype, w_lhs, w_rhs)
         w_lhs.add_invalidates(w_res)
         w_rhs.add_invalidates(w_res)
         return w_res
diff --git a/pypy/module/micronumpy/signature.py b/pypy/module/micronumpy/signature.py
--- a/pypy/module/micronumpy/signature.py
+++ b/pypy/module/micronumpy/signature.py
@@ -49,4 +49,4 @@
     _immutable_fields_ = ["func"]
 
     def __init__(self, func):
-        self.func = func
\ No newline at end of file
+        self.func = func
diff --git a/pypy/module/micronumpy/test/test_base.py b/pypy/module/micronumpy/test/test_base.py
--- a/pypy/module/micronumpy/test/test_base.py
+++ b/pypy/module/micronumpy/test/test_base.py
@@ -1,6 +1,6 @@
 from pypy.conftest import gettestobjspace
 from pypy.module.micronumpy.interp_dtype import get_dtype_cache
-from pypy.module.micronumpy.interp_numarray import SingleDimArray, Scalar
+from pypy.module.micronumpy.interp_numarray import NDimArray, Scalar
 from pypy.module.micronumpy.interp_ufuncs import (find_binop_result_dtype,
         find_unaryop_result_dtype)
 
@@ -14,7 +14,7 @@
         float64_dtype = get_dtype_cache(space).w_float64dtype
         bool_dtype = get_dtype_cache(space).w_booldtype
 
-        ar = SingleDimArray(10, dtype=float64_dtype)
+        ar = NDimArray(10, [10], dtype=float64_dtype)
         v1 = ar.descr_add(space, ar)
         v2 = ar.descr_add(space, Scalar(float64_dtype, 2.0))
         assert v1.signature is not v2.signature
@@ -23,7 +23,7 @@
         v4 = ar.descr_add(space, ar)
         assert v1.signature is v4.signature
 
-        bool_ar = SingleDimArray(10, dtype=bool_dtype)
+        bool_ar = NDimArray(10, [10], dtype=bool_dtype)
         v5 = ar.descr_add(space, bool_ar)
         assert v5.signature is not v1.signature
         assert v5.signature is not v2.signature
@@ -33,13 +33,13 @@
     def test_slice_signature(self, space):
         float64_dtype = get_dtype_cache(space).w_float64dtype
 
-        ar = SingleDimArray(10, dtype=float64_dtype)
-        v1 = ar.descr_getitem(space, space.wrap(slice(1, 5, 1)))
+        ar = NDimArray(10, [10], dtype=float64_dtype)
+        v1 = ar.descr_getitem(space, space.wrap(slice(1, 3, 1)))
         v2 = ar.descr_getitem(space, space.wrap(slice(4, 6, 1)))
         assert v1.signature is v2.signature
 
-        v3 = ar.descr_add(space, v1)
-        v4 = ar.descr_add(space, v2)
+        v3 = v2.descr_add(space, v1)
+        v4 = v1.descr_add(space, v2)
         assert v3.signature is v4.signature
 
 class TestUfuncCoerscion(object):
diff --git a/pypy/module/micronumpy/test/test_compile.py b/pypy/module/micronumpy/test/test_compile.py
--- a/pypy/module/micronumpy/test/test_compile.py
+++ b/pypy/module/micronumpy/test/test_compile.py
@@ -102,10 +102,11 @@
         code = """
         a = [1,2,3,4]
         b = [4,5,6,5]
-        a + b
+        c = a + b
+        c -> 3
         """
         interp = self.run(code)
-        assert interp.results[0]._getnums(False) == ["5.0", "7.0", "9.0", "9.0"]
+        assert interp.results[-1].value == 9
 
     def test_array_getitem(self):
         code = """
@@ -114,7 +115,7 @@
         a + b -> 3
         """
         interp = self.run(code)
-        assert interp.results[0].value.value == 3 + 6
+        assert interp.results[0].value == 3 + 6
 
     def test_range_getitem(self):
         code = """
@@ -122,7 +123,7 @@
         r -> 3
         """
         interp = self.run(code)
-        assert interp.results[0].value.value == 6
+        assert interp.results[0].value == 6
 
     def test_sum(self):
         code = """
@@ -140,7 +141,7 @@
         a -> 3
         """
         interp = self.run(code)
-        assert interp.results[0].value.value == 15
+        assert interp.results[0].value == 15
 
     def test_min(self):
         interp = self.run("""
@@ -161,10 +162,32 @@
         assert interp.results[0].value.value == 256
 
     def test_slice(self):
-        py.test.skip("in progress")
         interp = self.run("""
         a = [1,2,3,4]
         b = a -> :
         b -> 3
         """)
-        assert interp.results[0].value.val == 3
+        assert interp.results[0].value == 4
+
+    def test_slice_step(self):
+        interp = self.run("""
+        a = |30|
+        b = a -> ::2
+        b -> 3
+        """)
+        assert interp.results[0].value == 6
+
+    def test_multidim_getitem(self):
+        interp = self.run("""
+        a = [[1,2]]
+        a -> 0 -> 1
+        """)
+        assert interp.results[0].value == 2
+
+    def test_multidim_getitem_2(self):
+        interp = self.run("""
+        a = [[1, 2], [3, 4], [5, 6], [7, 8], [9, 10]]
+        b = a + a
+        b -> 1 -> 1
+        """)
+        assert interp.results[0].value == 8
diff --git a/pypy/module/micronumpy/test/test_numarray.py b/pypy/module/micronumpy/test/test_numarray.py
--- a/pypy/module/micronumpy/test/test_numarray.py
+++ b/pypy/module/micronumpy/test/test_numarray.py
@@ -1,6 +1,157 @@
+
+import py
 from pypy.module.micronumpy.test.test_base import BaseNumpyAppTest
+from pypy.module.micronumpy.interp_numarray import NDimArray, shape_agreement
+from pypy.module.micronumpy import signature
+from pypy.interpreter.error import OperationError
 from pypy.conftest import gettestobjspace
 
+class MockDtype(object):
+    signature = signature.BaseSignature()
+    def malloc(self, size):
+        return None
+
+class TestNumArrayDirect(object):
+    def newslice(self, *args):
+        return self.space.newslice(*[self.space.wrap(arg) for arg in args])
+
+    def newtuple(self, *args):
+        args_w = []
+        for arg in args:
+            if isinstance(arg, int):
+                args_w.append(self.space.wrap(arg))
+            else:
+                args_w.append(arg)
+        return self.space.newtuple(args_w)
+
+    def test_strides_f(self):
+        a = NDimArray(100, [10, 5, 3], MockDtype(), 'F')
+        assert a.strides == [1, 10, 50]
+        assert a.backstrides == [9, 40, 100]
+
+    def test_strides_c(self):
+        a = NDimArray(100, [10, 5, 3], MockDtype(), 'C')
+        assert a.strides == [15, 3, 1]
+        assert a.backstrides == [135, 12, 2]
+
+    def test_create_slice_f(self):
+        space = self.space
+        a = NDimArray(10 * 5 * 3, [10, 5, 3], MockDtype(), 'F')
+        s = a.create_slice(space, [(3, 0, 0, 1)])
+        assert s.start == 3
+        assert s.strides == [10, 50]
+        assert s.backstrides == [40, 100]
+        s = a.create_slice(space, [(1, 9, 2, 4)])
+        assert s.start == 1
+        assert s.strides == [2, 10, 50]
+        assert s.backstrides == [6, 40, 100]
+        s = a.create_slice(space, [(1, 5, 3, 2), (1, 2, 1, 1), (1, 0, 0, 1)])
+        assert s.shape == [2, 1]
+        assert s.strides == [3, 10]
+        assert s.backstrides == [3, 0]
+        s = a.create_slice(space, [(0, 10, 1, 10), (2, 0, 0, 1)])
+        assert s.start == 20
+        assert s.shape == [10, 3]
+
+    def test_create_slice_c(self):
+        space = self.space
+        a = NDimArray(10 * 5 * 3, [10, 5, 3], MockDtype(), 'C')
+        s = a.create_slice(space, [(3, 0, 0, 1)])
+        assert s.start == 45
+        assert s.strides == [3, 1]
+        assert s.backstrides == [12, 2]
+        s = a.create_slice(space, [(1, 9, 2, 4)])
+        assert s.start == 15
+        assert s.strides == [30, 3, 1]
+        assert s.backstrides == [90, 12, 2]
+        s = a.create_slice(space, [(1, 5, 3, 2), (1, 2, 1, 1), (1, 0, 0, 1)])
+        assert s.start == 19
+        assert s.shape == [2, 1]
+        assert s.strides == [45, 3]
+        assert s.backstrides == [45, 0]
+        s = a.create_slice(space, [(0, 10, 1, 10), (2, 0, 0, 1)])
+        assert s.start == 6
+        assert s.shape == [10, 3]
+
+    def test_slice_of_slice_f(self):
+        space = self.space
+        a = NDimArray(10 * 5 * 3, [10, 5, 3], MockDtype(), 'F')
+        s = a.create_slice(space, [(5, 0, 0, 1)])
+        assert s.start == 5
+        s2 = s.create_slice(space, [(3, 0, 0, 1)])
+        assert s2.shape == [3]
+        assert s2.strides == [50]
+        assert s2.parent is a
+        assert s2.backstrides == [100]
+        assert s2.start == 35
+        s = a.create_slice(space, [(1, 5, 3, 2)])
+        s2 = s.create_slice(space, [(0, 2, 1, 2), (2, 0, 0, 1)])
+        assert s2.shape == [2, 3]
+        assert s2.strides == [3, 50]
+        assert s2.backstrides == [3, 100]
+        assert s2.start == 1 * 15 + 2 * 3
+
+    def test_slice_of_slice_c(self):
+        space = self.space
+        a = NDimArray(10 * 5 * 3, [10, 5, 3], MockDtype(), order='C')
+        s = a.create_slice(space, [(5, 0, 0, 1)])
+        assert s.start == 15 * 5
+        s2 = s.create_slice(space, [(3, 0, 0, 1)])
+        assert s2.shape == [3]
+        assert s2.strides == [1]
+        assert s2.parent is a
+        assert s2.backstrides == [2]
+        assert s2.start == 5 * 15 + 3 * 3
+        s = a.create_slice(space, [(1, 5, 3, 2)])
+        s2 = s.create_slice(space, [(0, 2, 1, 2), (2, 0, 0, 1)])
+        assert s2.shape == [2, 3]
+        assert s2.strides == [45, 1]
+        assert s2.backstrides == [45, 2]
+        assert s2.start == 1 * 15 + 2 * 3
+
+    def test_negative_step_f(self):
+        space = self.space
+        a = NDimArray(10 * 5 * 3, [10, 5, 3], MockDtype(), 'F')
+        s = a.create_slice(space, [(9, -1, -2, 5)])
+        assert s.start == 9
+        assert s.strides == [-2, 10, 50]
+        assert s.backstrides == [-8, 40, 100]
+
+    def test_negative_step_c(self):
+        space = self.space
+        a = NDimArray(10 * 5 * 3, [10, 5, 3], MockDtype(), order='C')
+        s = a.create_slice(space, [(9, -1, -2, 5)])
+        assert s.start == 135
+        assert s.strides == [-30, 3, 1]
+        assert s.backstrides == [-120, 12, 2]
+
+    def test_index_of_single_item_f(self):
+        a = NDimArray(10 * 5 * 3, [10, 5, 3], MockDtype(), 'F')
+        r = a._index_of_single_item(self.space, self.newtuple(1, 2, 2))
+        assert r == 1 + 2 * 10 + 2 * 50
+        s = a.create_slice(self.space, [(0, 10, 1, 10), (2, 0, 0, 1)])
+        r = s._index_of_single_item(self.space, self.newtuple(1, 0))
+        assert r == a._index_of_single_item(self.space, self.newtuple(1, 2, 0))
+        r = s._index_of_single_item(self.space, self.newtuple(1, 1))
+        assert r == a._index_of_single_item(self.space, self.newtuple(1, 2, 1))
+
+    def test_index_of_single_item_c(self):
+        a = NDimArray(10 * 5 * 3, [10, 5, 3], MockDtype(), 'C')
+        r = a._index_of_single_item(self.space, self.newtuple(1, 2, 2))
+        assert r == 1 * 3 * 5 + 2 * 3 + 2
+        s = a.create_slice(self.space, [(0, 10, 1, 10), (2, 0, 0, 1)])
+        r = s._index_of_single_item(self.space, self.newtuple(1, 0))
+        assert r == a._index_of_single_item(self.space, self.newtuple(1, 2, 0))
+        r = s._index_of_single_item(self.space, self.newtuple(1, 1))
+        assert r == a._index_of_single_item(self.space, self.newtuple(1, 2, 1))
+
+    def test_shape_agreement(self):
+        assert shape_agreement(self.space, [3], [3]) == [3]
+        assert shape_agreement(self.space, [1, 2, 3], [1, 2, 3]) == [1, 2, 3]
+        py.test.raises(OperationError, shape_agreement, self.space, [2], [3])
+        assert shape_agreement(self.space, [4, 4], []) == [4, 4]
+        assert shape_agreement(self.space, [8, 1, 6, 1], [7, 1, 5]) == [8, 7, 6, 5]
+        assert shape_agreement(self.space, [5, 2], [4, 3, 5, 2]) == [4, 3, 5, 2]
 
 class AppTestNumArray(BaseNumpyAppTest):
     def test_type(self):
@@ -50,63 +201,16 @@
         b = a.copy()
         for i in xrange(5):
             assert b[i] == a[i]
+        a[3] = 22
+        assert b[3] == 3
 
     def test_iterator_init(self):
         from numpypy import array
         a = array(range(5))
         assert a[3] == 3
-
-    def test_repr(self):
-        from numpypy import array, zeros
-        a = array(range(5), float)
-        assert repr(a) == "array([0.0, 1.0, 2.0, 3.0, 4.0])"
-        a = array([], float)
-        assert repr(a) == "array([], dtype=float64)"
-        a = zeros(1001)
-        assert repr(a) == "array([0.0, 0.0, 0.0, ..., 0.0, 0.0, 0.0])"
-        a = array(range(5), long)
-        assert repr(a) == "array([0, 1, 2, 3, 4])"
-        a = array([], long)
-        assert repr(a) == "array([], dtype=int64)"
-        a = array([True, False, True, False], "?")
-        assert repr(a) == "array([True, False, True, False], dtype=bool)"
-
-    def test_repr_slice(self):
-        from numpypy import array, zeros
-        a = array(range(5), float)
-        b = a[1::2]
-        assert repr(b) == "array([1.0, 3.0])"
-        a = zeros(2002)
-        b = a[::2]
-        assert repr(b) == "array([0.0, 0.0, 0.0, ..., 0.0, 0.0, 0.0])"
-
-    def test_str(self):
-        from numpypy import array, zeros
-        a = array(range(5), float)
-        assert str(a) == "[0.0 1.0 2.0 3.0 4.0]"
-        assert str((2*a)[:]) == "[0.0 2.0 4.0 6.0 8.0]"
-        a = zeros(1001)
-        assert str(a) == "[0.0 0.0 0.0 ..., 0.0 0.0 0.0]"
-
-        a = array(range(5), dtype=long)
-        assert str(a) == "[0 1 2 3 4]"
-        a = array([True, False, True, False], dtype="?")
-        assert str(a) == "[True False True False]"
-
-        a = array(range(5), dtype="int8")
-        assert str(a) == "[0 1 2 3 4]"
-
-        a = array(range(5), dtype="int16")
-        assert str(a) == "[0 1 2 3 4]"
-
-    def test_str_slice(self):
-        from numpypy import array, zeros
-        a = array(range(5), float)
-        b = a[1::2]
-        assert str(b) == "[1.0 3.0]"
-        a = zeros(2002)
-        b = a[::2]
-        assert str(b) == "[0.0 0.0 0.0 ..., 0.0 0.0 0.0]"
+        a = array(1)
+        assert a[0] == 1
+        assert a.shape == ()
 
     def test_getitem(self):
         from numpypy import array
@@ -140,8 +244,8 @@
         a = array(range(5))
         raises(IndexError, "a[(1,2)] = [0,1]")
         for i in xrange(5):
-            a[(i,)] = i+1
-            assert a[i] == i+1
+            a[(i,)] = i + 1
+            assert a[i] == i + 1
         a[()] = range(5)
         for i in xrange(5):
             assert a[i] == i
@@ -171,7 +275,7 @@
         assert a[3] == 1.
         assert a[4] == 11.
         a = zeros(10)
-        a[::2][::-1][::2] = array(range(1,4))
+        a[::2][::-1][::2] = array(range(1, 4))
         assert a[8] == 1.
         assert a[4] == 2.
         assert a[0] == 3.
@@ -191,6 +295,11 @@
         assert a[1] == 0.
         assert a[3] == 0.
 
+    def test_scalar(self):
+        from numpypy import array
+        a = array(3)
+        assert a[0] == 3
+
     def test_len(self):
         from numpypy import array
         a = array(range(5))
@@ -222,7 +331,7 @@
     def test_add_other(self):
         from numpypy import array
         a = array(range(5))
-        b = array(range(4, -1, -1))
+        b = array([i for i in reversed(range(5))])
         c = a + b
         for i in range(5):
             assert c[i] == 4
@@ -346,8 +455,8 @@
         a = array(range(5), float)
         b = a ** a
         for i in range(5):
-            print b[i], i**i
-            assert b[i] == i**i
+            print b[i], i ** i
+            assert b[i] == i ** i
 
     def test_pow_other(self):
         from numpypy import array
@@ -366,7 +475,7 @@
 
     def test_mod(self):
         from numpypy import array
-        a = array(range(1,6))
+        a = array(range(1, 6))
         b = a % a
         for i in range(5):
             assert b[i] == 0
@@ -394,7 +503,7 @@
 
     def test_pos(self):
         from numpypy import array
-        a = array([1.,-2.,3.,-4.,-5.])
+        a = array([1., -2., 3., -4., -5.])
         b = +a
         for i in range(5):
             assert b[i] == a[i]
@@ -405,7 +514,7 @@
 
     def test_neg(self):
         from numpypy import array
-        a = array([1.,-2.,3.,-4.,-5.])
+        a = array([1., -2., 3., -4., -5.])
         b = -a
         for i in range(5):
             assert b[i] == -a[i]
@@ -416,7 +525,7 @@
 
     def test_abs(self):
         from numpypy import array
-        a = array([1.,-2.,3.,-4.,-5.])
+        a = array([1., -2., 3., -4., -5.])
         b = abs(a)
         for i in range(5):
             assert b[i] == abs(a[i])
@@ -445,7 +554,7 @@
         s = a[1:5]
         assert len(s) == 4
         for i in range(4):
-            assert s[i] == a[i+1]
+            assert s[i] == a[i + 1]
 
         s = (a + a)[1:2]
         assert len(s) == 1
@@ -459,7 +568,7 @@
         s = a[1:9:2]
         assert len(s) == 4
         for i in range(4):
-            assert s[i] == a[2*i+1]
+            assert s[i] == a[2 * i + 1]
 
     def test_slice_update(self):
         from numpypy import array
@@ -470,13 +579,12 @@
         a[2] = 20
         assert s[2] == 20
 
-
     def test_slice_invaidate(self):
         # check that slice shares invalidation list with
         from numpypy import array
         a = array(range(5))
         s = a[0:2]
-        b = array([10,11])
+        b = array([10, 11])
         c = s + b
         a[0] = 100
         assert c[0] == 10
@@ -503,7 +611,7 @@
 
     def test_prod(self):
         from numpypy import array
-        a = array(range(1,6))
+        a = array(range(1, 6))
         assert a.prod() == 120.0
         assert a[:4].prod() == 24.0
 
@@ -517,7 +625,7 @@
     def test_max_add(self):
         from numpypy import array
         a = array([-1.2, 3.4, 5.7, -3.0, 2.7])
-        assert (a+a).max() == 11.4
+        assert (a + a).max() == 11.4
 
     def test_min(self):
         from numpypy import array
@@ -529,12 +637,23 @@
     def test_argmax(self):
         from numpypy import array
         a = array([-1.2, 3.4, 5.7, -3.0, 2.7])
-        assert a.argmax() == 2
+        r = a.argmax()
+        assert r == 2
         b = array([])
-        raises(ValueError, "b.argmax()")
+        raises(ValueError, b.argmax)
 
         a = array(range(-5, 5))
-        assert a.argmax() == 9
+        r = a.argmax()
+        assert r == 9
+        b = a[::2]
+        r = b.argmax()
+        assert r == 4
+        r = (a + a).argmax()
+        assert r == 9
+        a = array([1, 0, 0])
+        assert a.argmax() == 0
+        a = array([0, 0, 1])
+        assert a.argmax() == 2
 
     def test_argmin(self):
         from numpypy import array
@@ -612,6 +731,201 @@
             for i in xrange(5):
                 assert c[i] == func(b[i], 3)
 
+    def test_nonzero(self):
+        from numpypy import array
+        a = array([1, 2])
+        raises(ValueError, bool, a)
+        raises(ValueError, bool, a == a)
+        assert bool(array(1))
+        assert not bool(array(0))
+        assert bool(array([1]))
+        assert not bool(array([0]))
+
+class AppTestMultiDim(BaseNumpyAppTest):
+    def test_init(self):
+        import numpypy
+        a = numpypy.zeros((2, 2))
+        assert len(a) == 2
+
+    def test_shape(self):
+        import numpypy
+        assert numpypy.zeros(1).shape == (1,)
+        assert numpypy.zeros((2, 2)).shape == (2, 2)
+        assert numpypy.zeros((3, 1, 2)).shape == (3, 1, 2)
+        assert numpypy.array([[1], [2], [3]]).shape == (3, 1)
+        assert len(numpypy.zeros((3, 1, 2))) == 3
+        raises(TypeError, len, numpypy.zeros(()))
+        raises(ValueError, numpypy.array, [[1, 2], 3])
+
+    def test_getsetitem(self):
+        import numpypy
+        a = numpypy.zeros((2, 3, 1))
+        raises(IndexError, a.__getitem__, (2, 0, 0))
+        raises(IndexError, a.__getitem__, (0, 3, 0))
+        raises(IndexError, a.__getitem__, (0, 0, 1))
+        assert a[1, 1, 0] == 0
+        a[1, 2, 0] = 3
+        assert a[1, 2, 0] == 3
+        assert a[1, 1, 0] == 0
+        assert a[1, -1, 0] == 3
+
+    def test_slices(self):
+        import numpypy
+        a = numpypy.zeros((4, 3, 2))
+        raises(IndexError, a.__getitem__, (4,))
+        raises(IndexError, a.__getitem__, (3, 3))
+        raises(IndexError, a.__getitem__, (slice(None), 3))
+        a[0, 1, 1] = 13
+        a[1, 2, 1] = 15
+        b = a[0]
+        assert len(b) == 3
+        assert b.shape == (3, 2)
+        assert b[1, 1] == 13
+        b = a[1]
+        assert b.shape == (3, 2)
+        assert b[2, 1] == 15
+        b = a[:, 1]
+        assert b.shape == (4, 2)
+        assert b[0, 1] == 13
+        b = a[:, 1, :]
+        assert b.shape == (4, 2)
+        assert b[0, 1] == 13
+        b = a[1, 2]
+        assert b[1] == 15
+        b = a[:]
+        assert b.shape == (4, 3, 2)
+        assert b[1, 2, 1] == 15
+        assert b[0, 1, 1] == 13
+        b = a[:][:, 1][:]
+        assert b[2, 1] == 0.0
+        assert b[0, 1] == 13
+        raises(IndexError, b.__getitem__, (4, 1))
+        assert a[0][1][1] == 13
+        assert a[1][2][1] == 15
+
+    def test_init_2(self):
+        import numpypy
+        raises(ValueError, numpypy.array, [[1], 2])
+        raises(ValueError, numpypy.array, [[1, 2], [3]])
+        raises(ValueError, numpypy.array, [[[1, 2], [3, 4], 5]])
+        raises(ValueError, numpypy.array, [[[1, 2], [3, 4], [5]]])
+        a = numpypy.array([[1, 2], [4, 5]])
+        assert a[0, 1] == 2
+        assert a[0][1] == 2
+        a = numpypy.array(([[[1, 2], [3, 4], [5, 6]]]))
+        assert (a[0, 1] == [3, 4]).all()
+
+    def test_setitem_slice(self):
+        import numpypy
+        a = numpypy.zeros((3, 4))
+        a[1] = [1, 2, 3, 4]
+        assert a[1, 2] == 3
+        raises(TypeError, a[1].__setitem__, [1, 2, 3])
+        a = numpypy.array([[1, 2], [3, 4]])
+        assert (a == [[1, 2], [3, 4]]).all()
+        a[1] = numpypy.array([5, 6])
+        assert (a == [[1, 2], [5, 6]]).all()
+        a[:, 1] = numpypy.array([8, 10])
+        assert (a == [[1, 8], [5, 10]]).all()
+        a[0, :: -1] = numpypy.array([11, 12])
+        assert (a == [[12, 11], [5, 10]]).all()
+
+    def test_ufunc(self):
+        from numpypy import array
+        a = array([[1, 2], [3, 4], [5, 6]])
+        assert ((a + a) == array([[1 + 1, 2 + 2], [3 + 3, 4 + 4], [5 + 5, 6 + 6]])).all()
+
+    def test_getitem_add(self):
+        from numpypy import array
+        a = array([[1, 2], [3, 4], [5, 6], [7, 8], [9, 10]])
+        assert (a + a)[1, 1] == 8
+
+    def test_ufunc_negative(self):
+        from numpypy import array, negative
+        a = array([[1, 2], [3, 4]])
+        b = negative(a + a)
+        assert (b == [[-2, -4], [-6, -8]]).all()
+
+    def test_getitem_3(self):
+        from numpypy import array
+        a = array([[1, 2], [3, 4], [5, 6], [7, 8], [9, 10], [11, 12], [13, 14]])
+        b = a[::2]
+        print a
+        print b
+        assert (b == [[1, 2], [5, 6], [9, 10], [13, 14]]).all()
+        c = b + b
+        assert c[1][1] == 12
+
+    def test_multidim_ones(self):
+        from numpypy import ones
+        a = ones((1, 2, 3))
+        assert a[0, 1, 2] == 1.0
+
+    def test_broadcast_ufunc(self):
+        from numpypy import array
+        a = array([[1, 2], [3, 4], [5, 6]])
+        b = array([5, 6])
+        c = ((a + b) == [[1 + 5, 2 + 6], [3 + 5, 4 + 6], [5 + 5, 6 + 6]])
+        assert c.all()
+
+    def test_broadcast_setslice(self):
+        from numpypy import zeros, ones
+        a = zeros((100, 100))
+        b = ones(100)
+        a[:, :] = b
+        assert a[13, 15] == 1
+
+    def test_broadcast_shape_agreement(self):
+        from numpypy import zeros, array
+        a = zeros((3, 1, 3))
+        b = array(((10, 11, 12), (20, 21, 22), (30, 31, 32)))
+        c = ((a + b) == [b, b, b])
+        assert c.all()
+        a = array((((10,11,12), ), ((20, 21, 22), ), ((30,31,32), )))
+        assert(a.shape == (3, 1, 3))
+        d = zeros((3, 3))
+        c = ((a + d) == [b, b, b])
+        c = ((a + d) == array([[[10., 11., 12.]]*3, [[20.,21.,22.]]*3, [[30.,31.,32.]]*3]))
+        assert c.all()
+
+    def test_broadcast_scalar(self):
+        from numpypy import zeros
+        a = zeros((4, 5), 'd')
+        a[:, 1] = 3
+        assert a[2, 1] == 3
+        assert a[0, 2] == 0
+        a[0, :] = 5
+        assert a[0, 3] == 5
+        assert a[2, 1] == 3
+        assert a[3, 2] == 0
+
+    def test_broadcast_call2(self):
+        from numpypy import zeros, ones
+        a = zeros((4, 1, 5))
+        b = ones((4, 3, 5))
+        b[:] = (a + a)
+        assert (b == zeros((4, 3, 5))).all()
+
+    def test_argmax(self):
+        from numpypy import array
+        a = array([[1, 2], [3, 4], [5, 6]])
+        assert a.argmax() == 5
+        assert a[:2,].argmax() == 3
+
+    def test_broadcast_wrong_shapes(self):
+        from numpypy import zeros
+        a = zeros((4, 3, 2))
+        b = zeros((4, 2))
+        exc = raises(ValueError, lambda: a + b)
+        assert str(exc.value) == "operands could not be broadcast together with shapes (4,3,2) (4,2)"
+
+    def test_reduce(self):
+        from numpypy import array
+        a = array([[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]])
+        assert a.sum() == (13 * 12) / 2
+        b = a[1:, 1::2]
+        c = b + b
+        assert c.sum() == (6 + 8 + 10 + 12) * 2
 
 class AppTestSupport(BaseNumpyAppTest):
     def setup_class(cls):
@@ -625,3 +939,94 @@
         for i in range(4):
             assert a[i] == i + 1
         raises(ValueError, fromstring, "abc")
+
+class AppTestRepr(BaseNumpyAppTest):
+    def test_repr(self):
+        from numpypy import array, zeros
+        a = array(range(5), float)
+        assert repr(a) == "array([0.0, 1.0, 2.0, 3.0, 4.0])"
+        a = array([], float)
+        assert repr(a) == "array([], dtype=float64)"
+        a = zeros(1001)
+        assert repr(a) == "array([0.0, 0.0, 0.0, ..., 0.0, 0.0, 0.0])"
+        a = array(range(5), long)
+        assert repr(a) == "array([0, 1, 2, 3, 4])"
+        a = array([], long)
+        assert repr(a) == "array([], dtype=int64)"
+        a = array([True, False, True, False], "?")
+        assert repr(a) == "array([True, False, True, False], dtype=bool)"
+
+    def test_repr_multi(self):
+        from numpypy import array, zeros
+        a = zeros((3, 4))
+        assert repr(a) == '''array([[0.0, 0.0, 0.0, 0.0],
+       [0.0, 0.0, 0.0, 0.0],
+       [0.0, 0.0, 0.0, 0.0]])'''
+        a = zeros((2, 3, 4))
+        assert repr(a) == '''array([[[0.0, 0.0, 0.0, 0.0],
+        [0.0, 0.0, 0.0, 0.0],
+        [0.0, 0.0, 0.0, 0.0]],
+
+       [[0.0, 0.0, 0.0, 0.0],
+        [0.0, 0.0, 0.0, 0.0],
+        [0.0, 0.0, 0.0, 0.0]]])'''
+
+    def test_repr_slice(self):
+        from numpypy import array, zeros
+        a = array(range(5), float)
+        b = a[1::2]
+        assert repr(b) == "array([1.0, 3.0])"
+        a = zeros(2002)
+        b = a[::2]
+        assert repr(b) == "array([0.0, 0.0, 0.0, ..., 0.0, 0.0, 0.0])"
+        a = array((range(5), range(5, 10)), dtype="int16")
+        b = a[1, 2:]
+        assert repr(b) == "array([7, 8, 9], dtype=int16)"
+        # an empty slice prints its shape
+        b = a[2:1, ]
+        assert repr(b) == "array([], shape=(0, 5), dtype=int16)"
+
+    def test_str(self):
+        from numpypy import array, zeros
+        a = array(range(5), float)
+        assert str(a) == "[0.0 1.0 2.0 3.0 4.0]"
+        assert str((2 * a)[:]) == "[0.0 2.0 4.0 6.0 8.0]"
+        a = zeros(1001)
+        assert str(a) == "[0.0 0.0 0.0 ..., 0.0 0.0 0.0]"
+
+        a = array(range(5), dtype=long)
+        assert str(a) == "[0 1 2 3 4]"
+        a = array([True, False, True, False], dtype="?")
+        assert str(a) == "[True False True False]"
+
+        a = array(range(5), dtype="int8")
+        assert str(a) == "[0 1 2 3 4]"
+
+        a = array(range(5), dtype="int16")
+        assert str(a) == "[0 1 2 3 4]"
+
+        a = array((range(5), range(5, 10)), dtype="int16")
+        assert str(a) == "[[0 1 2 3 4]\n [5 6 7 8 9]]"
+
+        a = array(3, dtype=int)
+        assert str(a) == "3"
+
+        a = zeros((400, 400), dtype=int)
+        assert str(a) == "[[0 0 0 ..., 0 0 0]\n [0 0 0 ..., 0 0 0]\n [0 0 0 ..., 0 0 0]\n ..., \n [0 0 0 ..., 0 0 0]\n [0 0 0 ..., 0 0 0]\n [0 0 0 ..., 0 0 0]]"
+        a = zeros((2, 2, 2))
+        r = str(a)
+        assert r == '[[[0.0 0.0]\n  [0.0 0.0]]\n\n [[0.0 0.0]\n  [0.0 0.0]]]'
+
+    def test_str_slice(self):
+        from numpypy import array, zeros
+        a = array(range(5), float)
+        b = a[1::2]
+        assert str(b) == "[1.0 3.0]"
+        a = zeros(2002)
+        b = a[::2]
+        assert str(b) == "[0.0 0.0 0.0 ..., 0.0 0.0 0.0]"
+        a = array((range(5), range(5, 10)), dtype="int16")
+        b = a[1, 2:]
+        assert str(b) == "[7 8 9]"
+        b = a[2:1, ]
+        assert str(b) == "[]"
diff --git a/pypy/module/micronumpy/test/test_zjit.py b/pypy/module/micronumpy/test/test_zjit.py
--- a/pypy/module/micronumpy/test/test_zjit.py
+++ b/pypy/module/micronumpy/test/test_zjit.py
@@ -1,96 +1,132 @@
+
+""" Tests that check if JIT-compiled numpy operations produce reasonably
+good assembler
+"""
+
+import py
+
+from pypy.jit.metainterp import pyjitpl
 from pypy.jit.metainterp.test.support import LLJitMixin
+from pypy.jit.metainterp.warmspot import reset_stats
 from pypy.module.micronumpy import interp_boxes, interp_ufuncs, signature
-from pypy.module.micronumpy.compile import (FakeSpace,
-    FloatObject, IntObject, numpy_compile, BoolObject)
-from pypy.module.micronumpy.interp_numarray import (BaseArray, SingleDimArray,
-    SingleDimSlice)
+from pypy.module.micronumpy.compile import (numpy_compile, FakeSpace,
+    FloatObject, IntObject, BoolObject, Parser, InterpreterState)
+from pypy.module.micronumpy.interp_numarray import BaseArray, NDimArray, NDimSlice
 from pypy.rlib.nonconst import NonConstant
 from pypy.rpython.annlowlevel import llstr, hlstr
-from pypy.jit.metainterp.warmspot import reset_stats
-from pypy.jit.metainterp import pyjitpl
-
-import py
 
 
 class TestNumpyJIt(LLJitMixin):
     graph = None
     interp = None
 
-    def run(self, code):
+    def setup_class(cls):
+        default = """
+        a = [1,2,3,4]
+        c = a + b
+        sum(c) -> 1::1
+        a -> 3:1:2
+        """
+
+        d = {}
+        p = Parser()
+        allcodes = [p.parse(default)]
+        for name, meth in cls.__dict__.iteritems():
+            if name.startswith("define_"):
+                code = meth()
+                d[name[len("define_"):]] = len(allcodes)
+                allcodes.append(p.parse(code))
+        cls.code_mapping = d
+        cls.codes = allcodes
+
+    def run(self, name):
         space = FakeSpace()
+        i = self.code_mapping[name]
+        codes = self.codes
 
-        def f(code):
-            interp = numpy_compile(hlstr(code))
+        def f(i):
+            interp = InterpreterState(codes[i])
             interp.run(space)
             res = interp.results[-1]
             assert isinstance(res, BaseArray)
-            w_res = res.eval(0)
-            if isinstance(w_res, interp_boxes.W_BoolBox):
-                return float(w_res.value)
-            elif isinstance(w_res, interp_boxes.W_Float64Box):
-                return w_res.value
-            elif isinstance(w_res, interp_boxes.W_LongBox):
-                return w_res.value
+            w_res = res.eval(res.start_iter())
+            if isinstance(w_res, BoolObject):
+                return float(w_res.boolval)
+            elif isinstance(w_res, FloatObject):
+                return w_res.floatval
+            elif isinstance(w_res, IntObject):
+                return w_res.intval
             else:
                 return -42.
 
         if self.graph is None:
-            interp, graph = self.meta_interp(f, [llstr(code)],
+            interp, graph = self.meta_interp(f, [i],
                                              listops=True,
                                              backendopt=True,
                                              graph_and_interp_only=True)
             self.__class__.interp = interp
             self.__class__.graph = graph
-
         reset_stats()
         pyjitpl._warmrunnerdesc.memory_manager.alive_loops.clear()
-        return self.interp.eval_graph(self.graph, [llstr(code)])
+        return self.interp.eval_graph(self.graph, [i])
 
-    def test_add(self):
-        result = self.run("""
+    def define_add():
+        return """
         a = |30|
         b = a + a
         b -> 3
-        """)
-        self.check_loops({'getinteriorfield_raw': 2, 'float_add': 1,
-                          'setinteriorfield_raw': 1, 'int_add': 1,
-                          'int_lt': 1, 'guard_true': 1, 'jump': 1})
+        """
+
+    def test_add(self):
+        result = self.run("add")
+        self.check_loops({'getarrayitem_raw': 2, 'float_add': 1,
+                          'setarrayitem_raw': 1, 'int_add': 3,
+                          'int_ge': 1, 'guard_false': 1, 'jump': 1})
         assert result == 3 + 3
 
-    def test_floatadd(self):
-        result = self.run("""
+    def define_float_add():
+        return """
         a = |30| + 3
         a -> 3
-        """)
+        """
+
+    def test_floatadd(self):
+        result = self.run("float_add")
         assert result == 3 + 3
         self.check_loops({"getinteriorfield_raw": 1, "float_add": 1,
-                          "setinteriorfield_raw": 1, "int_add": 1,
-                          "int_lt": 1, "guard_true": 1, "jump": 1})
+                          "setinteriorfield_raw": 1, "int_add": 2,
+                          "int_ge": 1, "guard_false": 1, "jump": 1})
 
-    def test_sum(self):
-        result = self.run("""
+    def define_sum():
+        return """
         a = |30|
         b = a + a
         sum(b)
-        """)
+        """
+
+    def test_sum(self):
+        result = self.run("sum")
         assert result == 2 * sum(range(30))
         self.check_loops({"getinteriorfield_raw": 2, "float_add": 2,
-                          "int_add": 1,
-                          "int_lt": 1, "guard_true": 1, "jump": 1})
+                          "int_add": 2,
+                          "int_ge": 1, "guard_false": 1, "jump": 1})
 
-    def test_prod(self):
-        result = self.run("""
+    def define_prod():
+        return """
         a = |30|
         b = a + a
         prod(b)
-        """)
+        """
+
+    def test_prod(self):
+        result = self.run("prod")
         expected = 1
         for i in range(30):
             expected *= i * 2
         assert result == expected
         self.check_loops({"getinteriorfield_raw": 2, "float_add": 1,
-                          "float_mul": 1, "int_add": 1,
-                          "int_lt": 1, "guard_true": 1, "jump": 1})
+                          "float_mul": 1, "int_add": 2,
+                          "int_ge": 1, "guard_false": 1, "jump": 1})
 
     def test_max(self):
         py.test.skip("broken, investigate")
@@ -118,50 +154,59 @@
                           "float_mul": 1, "int_add": 1,
                           "int_lt": 1, "guard_true": 1, "jump": 1})
 
-    def test_any(self):
-        result = self.run("""
+    def define_any():
+        return """
         a = [0,0,0,0,0,0,0,0,0,0,0]
         a[8] = -12
         b = a + a
         any(b)
-        """)
+        """
+
+    def test_any(self):
+        result = self.run("any")
         assert result == 1
         self.check_loops({"getinteriorfield_raw": 2, "float_add": 1,
-                          "float_ne": 1, "int_add": 1,
-                          "int_lt": 1, "guard_true": 1, "jump": 1,
-                          "guard_false": 1})
+                          "float_ne": 1, "int_add": 2,
+                          "int_ge": 1, "jump": 1,
+                          "guard_false": 2})
 
-    def test_already_forced(self):
-        result = self.run("""
+    def define_already_forced():
+        return """
         a = |30|
         b = a + 4.5
         b -> 5 # forces
         c = b * 8
         c -> 5
-        """)
+        """
+
+    def test_already_forced(self):
+        result = self.run("already_forced")
         assert result == (5 + 4.5) * 8
         # This is the sum of the ops for both loops, however if you remove the
         # optimization then you end up with 2 float_adds, so we can still be
         # sure it was optimized correctly.
         self.check_loops({"getinteriorfield_raw": 2, "float_mul": 1, "float_add": 1,
-                          "setinteriorfield_raw": 2, "int_add": 2,
-                          "int_lt": 2, "guard_true": 2, "jump": 2})
+                          "setinteriorfield_raw": 2, "int_add": 4,
+                          "int_ge": 2, "guard_false": 2, "jump": 2})
 
-    def test_ufunc(self):
-        result = self.run("""
+    def define_ufunc():
+        return """
         a = |30|
         b = a + a
         c = unegative(b)
         c -> 3
-        """)
+        """
+
+    def test_ufunc(self):
+        result = self.run("ufunc")
         assert result == -6
         self.check_loops({"getinteriorfield_raw": 2, "float_add": 1, "float_neg": 1,
-                          "setinteriorfield_raw": 1, "int_add": 1,
-                          "int_lt": 1, "guard_true": 1, "jump": 1,
+                          "setinteriorfield_raw": 1, "int_add": 3,
+                          "int_ge": 1, "guard_false": 1, "jump": 1,
         })
 
-    def test_specialization(self):
-        self.run("""
+    def define_specialization():
+        return """
         a = |30|
         b = a + a
         c = unegative(b)
@@ -178,13 +223,78 @@
         d = a * a
         unegative(d)
         d -> 3
-        """)
+        """
+
+    def test_specialization(self):
+        self.run("specialization")
         # This is 3, not 2 because there is a bridge for the exit.
         self.check_loop_count(3)
 
+    def define_slice():
+        return """
+        a = |30|
+        b = a -> ::3
+        c = b + b
+        c -> 3
+        """
+
+    def test_slice(self):
+        result = self.run("slice")
+        assert result == 18
+        py.test.skip("Few remaining arraylen_gc left")
+        self.check_loops({'int_mul': 2, 'getarrayitem_raw': 2, 'float_add': 1,
+                          'setarrayitem_raw': 1, 'int_add': 3,
+                          'int_lt': 1, 'guard_true': 1, 'jump': 1})
+
+    def define_multidim():
+        return """
+        a = [[1, 2], [3, 4], [5, 6], [7, 8], [9, 10]]
+        b = a + a
+        b -> 1 -> 1
+        """
+
+    def test_multidim(self):
+        result = self.run('multidim')
+        assert result == 8
+        self.check_loops({'float_add': 1, 'getarrayitem_raw': 2,
+                          'guard_false': 1, 'int_add': 3, 'int_ge': 1,
+                          'jump': 1, 'setarrayitem_raw': 1})
+        # int_add might be 1 here if we try slightly harder with
+        # reusing indexes or some optimization
+
+    def define_multidim_slice():
+        return """
+        a = [[1, 2, 3, 4], [3, 4, 5, 6], [5, 6, 7, 8], [7, 8, 9, 10], [9, 10, 11, 12], [11, 12, 13, 14], [13, 14, 15, 16], [16, 17, 18, 19]]
+        b = a -> ::2
+        c = b + b
+        c -> 1 -> 1
+        """
+
+    def test_multidim_slice(self):
+        result = self.run('multidim_slice')
+        assert result == 12
+        py.test.skip("improve")
+        # XXX the bridge here is scary. Hopefully jit-targets will fix that,
+        #     otherwise it looks kind of good
+        self.check_loops({})
+
+    def define_broadcast():
+        return """
+        a = [[1, 2, 3, 4], [5, 6, 7, 8], [9, 10, 11, 12]]
+        b = [1, 2, 3, 4]
+        c = a + b
+        c -> 1 -> 2
+        """
+
+    def test_broadcast(self):
+        result = self.run("broadcast")
+        assert result == 10
+        py.test.skip("improve")
+        self.check_loops({})
 
 class TestNumpyOld(LLJitMixin):
     def setup_class(cls):
+        py.test.skip("old")
         from pypy.module.micronumpy.compile import FakeSpace
         from pypy.module.micronumpy.interp_dtype import get_dtype_cache
 
@@ -214,15 +324,15 @@
         def f(i):
             step1 = 2
             step2 = 3
-            ar = SingleDimArray(step2*i, dtype=self.float64_dtype)
+            ar = NDimArray(step2*i, dtype=self.float64_dtype)
             new_sig = signature.Signature.find_sig([
-                SingleDimSlice.signature, ar.signature
+                NDimSlice.signature, ar.signature
             ])
-            s1 = SingleDimSlice(0, step1*i, step1, i, ar, new_sig)
+            s1 = NDimSlice(0, step1*i, step1, i, ar, new_sig)
             new_sig = signature.Signature.find_sig([
-                SingleDimSlice.signature, s1.signature
+                NDimSlice.signature, s1.signature
             ])
-            s2 = SingleDimSlice(0, step2*i, step2, i, ar, new_sig)
+            s2 = NDimSlice(0, step2*i, step2, i, ar, new_sig)
             v = interp_ufuncs.get(self.space).add.call(self.space, [s1, s2])
             v = v.get_concrete().eval(3)
             assert isinstance(v, interp_boxes.W_Float64Box)
@@ -240,8 +350,8 @@
 
         def f(i):
             step = NonConstant(3)
-            ar = SingleDimArray(step*i, dtype=float64_dtype)
-            ar2 = SingleDimArray(i, dtype=float64_dtype)
+            ar = NDimArray(step*i, dtype=float64_dtype)
+            ar2 = NDimArray(i, dtype=float64_dtype)
             ar2.get_concrete().setitem(1, float64_dtype.box(5.5))
             arg = ar2.descr_add(space, ar2)
             ar.setslice(space, 0, step*i, step, i, arg)
@@ -269,7 +379,7 @@
                 dtype = float64_dtype
             else:
                 dtype = int32_dtype
-            ar = SingleDimArray(n, dtype=dtype)
+            ar = NDimArray(n, [n], dtype=dtype)
             i = 0
             while i < n:
                 ar.get_concrete().setitem(i, int32_dtype.box(7))
diff --git a/pypy/module/pyexpat/interp_pyexpat.py b/pypy/module/pyexpat/interp_pyexpat.py
--- a/pypy/module/pyexpat/interp_pyexpat.py
+++ b/pypy/module/pyexpat/interp_pyexpat.py
@@ -3,9 +3,7 @@
 from pypy.interpreter.gateway import NoneNotWrapped
 from pypy.interpreter.gateway import interp2app, unwrap_spec
 from pypy.interpreter.error import OperationError
-from pypy.objspace.descroperation import object_setattr
 from pypy.rlib import rgc
-from pypy.rlib.unroll import unrolling_iterable
 from pypy.rpython.lltypesystem import rffi, lltype
 from pypy.rpython.tool import rffi_platform
 from pypy.translator.tool.cbuild import ExternalCompilationInfo
@@ -339,8 +337,6 @@
     'XML_SetUnknownEncodingHandler',
     [XML_Parser, callback_type, rffi.VOIDP], lltype.Void)
 
-ENUMERATE_SETTERS = unrolling_iterable(SETTERS.items())
-
 # Declarations of external functions
 
 XML_ParserCreate = expat_external(
@@ -545,15 +541,19 @@
                 self.buffer_used = 0
         return False
 
+    def gethandler(self, space, name, index):
+        if name == 'CharacterDataHandler':
+            return self.w_character_data_handler or space.w_None
+        return self.handlers[index]
+
     def sethandler(self, space, name, w_handler, index, setter, handler):
-
         if name == 'CharacterDataHandler':
             self.flush_character_buffer(space)
             if space.is_w(w_handler, space.w_None):
                 self.w_character_data_handler = None
             else:
                 self.w_character_data_handler = w_handler
-
+        #
         self.handlers[index] = w_handler
         setter(self.itself, handler)
 
@@ -580,21 +580,29 @@
         return True
 
 
-    @unwrap_spec(name=str)
-    def setattr(self, space, name, w_value):
-        if name == "namespace_prefixes":
-            XML_SetReturnNSTriplet(self.itself, space.int_w(w_value))
-            return
+    @staticmethod
+    def _make_property(name):
+        index, setter, handler = SETTERS[name]
+        #
+        def descr_get_property(self, space):
+            return self.gethandler(space, name, index)
+        #
+        def descr_set_property(self, space, w_value):
+            return self.sethandler(space, name, w_value,
+                                   index, setter, handler)
+        #
+        return GetSetProperty(descr_get_property,
+                              descr_set_property,
+                              cls=W_XMLParserType)
 
-        for handler_name, (index, setter, handler) in ENUMERATE_SETTERS:
-            if name == handler_name:
-                return self.sethandler(space, handler_name, w_value,
-                                       index, setter, handler)
 
-        # fallback to object.__setattr__()
-        return space.call_function(
-            object_setattr(space),
-            space.wrap(self), space.wrap(name), w_value)
+    def get_namespace_prefixes(self, space):
+        raise OperationError(space.w_AttributeError,
+            space.wrap("not implemented: reading namespace_prefixes"))
+
+    @unwrap_spec(value=int)
+    def set_namespace_prefixes(self, space, value):
+        XML_SetReturnNSTriplet(self.itself, bool(value))
 
     # Parse methods
 
@@ -732,10 +740,18 @@
 if XML_COMBINED_VERSION >= 19505:
     XMLParser_methods.append('UseForeignDTD')
 
+_XMLParser_extras = {}
+for name in XMLParser_methods:
+    _XMLParser_extras[name] = interp2app(getattr(W_XMLParserType, name))
+for name in SETTERS:
+    _XMLParser_extras[name] = W_XMLParserType._make_property(name)
+
 W_XMLParserType.typedef = TypeDef(
     "pyexpat.XMLParserType",
     __doc__ = "XML parser",
-    __setattr__ = interp2app(W_XMLParserType.setattr),
+    namespace_prefixes = GetSetProperty(W_XMLParserType.get_namespace_prefixes,
+                                        W_XMLParserType.set_namespace_prefixes,
+                                        cls=W_XMLParserType),
     returns_unicode = bool_property('returns_unicode', W_XMLParserType),
     ordered_attributes = bool_property('ordered_attributes', W_XMLParserType),
     specified_attributes = bool_property('specified_attributes', W_XMLParserType),
@@ -754,8 +770,7 @@
     CurrentColumnNumber = GetSetProperty(W_XMLParserType.descr_ErrorColumnNumber, cls=W_XMLParserType),
     CurrentByteIndex = GetSetProperty(W_XMLParserType.descr_ErrorByteIndex, cls=W_XMLParserType),
 
-    **dict((name, interp2app(getattr(W_XMLParserType, name)))
-           for name in XMLParser_methods)
+    **_XMLParser_extras
     )
 
 def ParserCreate(space, w_encoding=None, w_namespace_separator=None,
diff --git a/pypy/module/pyexpat/test/test_parser.py b/pypy/module/pyexpat/test/test_parser.py
--- a/pypy/module/pyexpat/test/test_parser.py
+++ b/pypy/module/pyexpat/test/test_parser.py
@@ -52,6 +52,19 @@
                 assert res == 1
                 assert data == [u"\u00f6"]
 
+    def test_get_handler(self):
+        import pyexpat
+        p = pyexpat.ParserCreate()
+        assert p.StartElementHandler is None
+        assert p.EndElementHandler is None
+        def f(*args): pass
+        p.StartElementHandler = f
+        assert p.StartElementHandler is f
+        def g(*args): pass
+        p.EndElementHandler = g
+        assert p.StartElementHandler is f
+        assert p.EndElementHandler is g
+
     def test_intern(self):
         import pyexpat
         p = pyexpat.ParserCreate()
diff --git a/pypy/module/pypyjit/policy.py b/pypy/module/pypyjit/policy.py
--- a/pypy/module/pypyjit/policy.py
+++ b/pypy/module/pypyjit/policy.py
@@ -17,7 +17,7 @@
                        'imp', 'sys', 'array', '_ffi', 'itertools', 'operator',
                        'posix', '_socket', '_sre', '_lsprof', '_weakref',
                        '__pypy__', 'cStringIO', '_collections', 'struct',
-                       'mmap']:
+                       'mmap', 'marshal']:
             return True
         return False
 
diff --git a/pypy/module/pypyjit/test_pypy_c/model.py b/pypy/module/pypyjit/test_pypy_c/model.py
--- a/pypy/module/pypyjit/test_pypy_c/model.py
+++ b/pypy/module/pypyjit/test_pypy_c/model.py
@@ -271,7 +271,7 @@
         thread_ticker_check = """
             guard_not_invalidated?
             ticker0 = getfield_raw(ticker_address, descr=<SignedFieldDescr pypysig_long_struct.c_value .*>)
-            ticker1 = int_sub(ticker0, 1)
+            ticker1 = int_sub(ticker0, _)
             setfield_raw(ticker_address, ticker1, descr=<SignedFieldDescr pypysig_long_struct.c_value .*>)
             ticker_cond0 = int_lt(ticker1, 0)
             guard_false(ticker_cond0, descr=...)
diff --git a/pypy/module/pypyjit/test_pypy_c/test_call.py b/pypy/module/pypyjit/test_pypy_c/test_call.py
--- a/pypy/module/pypyjit/test_pypy_c/test_call.py
+++ b/pypy/module/pypyjit/test_pypy_c/test_call.py
@@ -334,26 +334,27 @@
         log = self.run(main, [1000])
         assert log.result == (1000, 998)
         loop, = log.loops_by_filename(self.filepath)
+        # the int strategy is used here
         assert loop.match_by_id('append', """
             i13 = getfield_gc(p8, descr=<SignedFieldDescr list.length .*>)
             i15 = int_add(i13, 1)
             # Will be killed by the backend
-            i17 = arraylen_gc(p7, descr=<GcPtrArrayDescr>)
-            call(ConstClass(_ll_list_resize_ge), p8, i15, descr=<VoidCallDescr>)
+            p15 = getfield_gc(p8, descr=<GcPtrFieldDescr list.items .*>)
+            i17 = arraylen_gc(p15, descr=<SignedArrayDescr>)
+            call(_, p8, i15, descr=<VoidCallDescr>) # this is a call to _ll_list_resize_ge_trampoline__...
             guard_no_exception(descr=...)
             p17 = getfield_gc(p8, descr=<GcPtrFieldDescr list.items .*>)
-            p19 = new_with_vtable(ConstClass(W_IntObject))
-            setfield_gc(p19, i12, descr=<SignedFieldDescr .*W_IntObject.inst_intval .*>)
-            setarrayitem_gc(p17, i13, p19, descr=<GcPtrArrayDescr>)
+            setarrayitem_gc(p17, i13, i12, descr=<SignedArrayDescr>)
         """)
 
     def test_blockstack_virtualizable(self):
         def main(n):
             from pypyjit import residual_call
+            l = len
             i = 0
             while i < n:
                 try:
-                    residual_call(len, [])   # ID: call
+                    residual_call(l, [])   # ID: call
                 except:
                     pass
                 i += 1
@@ -369,11 +370,8 @@
             p22 = new_with_vtable(19511408)
             p24 = new_array(1, descr=<GcPtrArrayDescr>)
             p26 = new_with_vtable(ConstClass(W_ListObject))
-            p27 = new(descr=<SizeDescr .*>)
-            p29 = new_array(0, descr=<GcPtrArrayDescr>)
             setfield_gc(p0, i20, descr=<SignedFieldDescr .*PyFrame.vable_token .*>)
-            setfield_gc(p27, p29, descr=<GcPtrFieldDescr list.items .*>)
-            setfield_gc(p26, p27, descr=<.* .*W_ListObject.inst_wrappeditems .*>)
+            setfield_gc(p26, ConstPtr(ptr22), descr=<GcPtrFieldDescr pypy.objspace.std.listobject.W_ListObject.inst_strategy .*>)
             setarrayitem_gc(p24, 0, p26, descr=<GcPtrArrayDescr>)
             setfield_gc(p22, p24, descr=<GcPtrFieldDescr .*Arguments.inst_arguments_w .*>)
             p32 = call_may_force(11376960, p18, p22, descr=<GcPtrCallDescr>)
@@ -486,4 +484,4 @@
             i4 = int_add(i0, 1)
             --TICK--
             jump(..., descr=...)
-        """)
\ No newline at end of file
+        """)
diff --git a/pypy/module/pypyjit/test_pypy_c/test_misc.py b/pypy/module/pypyjit/test_pypy_c/test_misc.py
--- a/pypy/module/pypyjit/test_pypy_c/test_misc.py
+++ b/pypy/module/pypyjit/test_pypy_c/test_misc.py
@@ -201,9 +201,11 @@
         assert log.result == 1000000
         loop, = log.loops_by_filename(self.filepath)
         assert loop.match("""
-            i16 = int_ge(i12, i13)
+            i14 = getfield_gc(p12, descr=<SignedFieldDescr list.length .*>)
+            i16 = uint_ge(i12, i14)
             guard_false(i16, descr=...)
-            p17 = getarrayitem_gc(p15, i12, descr=<GcPtrArrayDescr>)
+            p16 = getfield_gc(p12, descr=<GcPtrFieldDescr list.items .*>)
+            p17 = getarrayitem_gc(p16, i12, descr=<GcPtrArrayDescr>)
             i19 = int_add(i12, 1)
             setfield_gc(p9, i19, descr=<SignedFieldDescr .*W_AbstractSeqIterObject.inst_index .*>)
             guard_nonnull_class(p17, 146982464, descr=...)
@@ -217,7 +219,7 @@
             i28 = int_add_ovf(i10, i25)
             guard_no_overflow(descr=...)
             --TICK--
-            jump(p0, p1, p2, p3, p4, p5, p6, i28, i25, p9, p10, p11, i19, i13, p14, p15, descr=<Loop0>)
+            jump(p0, p1, p2, p3, p4, p5, p6, i28, i25, p9, p10, p11, p12, i19, descr=<Loop0>)
         """)
 
 
@@ -337,7 +339,7 @@
             a = compile('x+x+x+x+x+x', 'eval', 'eval')
             b = {'x': 7}
             while i < 1000:
-                y = eval(a,b,b)  # ID: eval
+                y = eval(a, b, b)  # ID: eval
                 i += 1
             return y
 
diff --git a/pypy/module/pypyjit/test_pypy_c/test_string.py b/pypy/module/pypyjit/test_pypy_c/test_string.py
--- a/pypy/module/pypyjit/test_pypy_c/test_string.py
+++ b/pypy/module/pypyjit/test_pypy_c/test_string.py
@@ -33,12 +33,8 @@
             i24 = int_ge(i19, i12)
             guard_false(i24, descr=...)
             i25 = unicodegetitem(p13, i19)
-            p27 = newstr(1)
-            strsetitem(p27, 0, i23)
-            p30 = call(ConstClass(ll_str2unicode__rpy_stringPtr), p27, descr=...)
-            guard_no_exception(descr=...)
-            i32 = call(ConstClass(_ll_2_str_eq_checknull_char__rpy_unicodePtr_UniChar), p30, i25, descr=...)
-            guard_true(i32, descr=...)
+            i26 = int_eq(i23, i25)
+            guard_true(i26, descr=...)
             i34 = int_add(i6, 1)
             --TICK--
             jump(p0, p1, p2, p3, p4, p5, i34, p7, p8, i9, i10, p11, i12, p13, descr=...)
@@ -147,8 +143,8 @@
             i31 = int_gt(i30, 23)
             guard_false(i31, descr=...)
             copystrcontent(p9, p21, 0, i25, i10)
-            i33 = int_eq(i30, 23)
-            guard_false(i33, descr=...)
+            i33 = int_lt(i30, 23)
+            guard_true(i33, descr=...)
             p35 = call(ConstClass(ll_shrink_array__rpy_stringPtr_Signed), p21, i30, descr=<GcPtrCallDescr>)
             guard_no_exception(descr=...)
             i37 = strlen(p35)
diff --git a/pypy/objspace/std/bytearrayobject.py b/pypy/objspace/std/bytearrayobject.py
--- a/pypy/objspace/std/bytearrayobject.py
+++ b/pypy/objspace/std/bytearrayobject.py
@@ -9,10 +9,7 @@
 from pypy.rlib.debug import check_annotation
 from pypy.objspace.std import stringobject
 from pypy.objspace.std.intobject import W_IntObject
-from pypy.objspace.std.listobject import (
-    _delitem_slice_helper, _setitem_slice_helper,
-    get_positive_index
-)
+from pypy.objspace.std.listobject import get_positive_index
 from pypy.objspace.std.listtype import get_list_index
 from pypy.objspace.std.sliceobject import W_SliceObject, normalize_simple_slice
 from pypy.objspace.std.stringobject import W_StringObject
@@ -600,7 +597,7 @@
     oldsize = len(w_bytearray.data)
     start, stop, step, slicelength = w_slice.indices4(space, oldsize)
     sequence2 = makebytearraydata_w(space, w_other)
-    setitem_slice_helper(space, w_bytearray.data, start, step, slicelength, sequence2, empty_elem='\x00')
+    _setitem_slice_helper(space, w_bytearray.data, start, step, slicelength, sequence2, empty_elem='\x00')
 
 def delitem__Bytearray_ANY(space, w_bytearray, w_idx):
     idx = get_list_index(space, w_idx)
@@ -614,13 +611,84 @@
 def delitem__Bytearray_Slice(space, w_bytearray, w_slice):
     start, stop, step, slicelength = w_slice.indices4(space,
                                                       len(w_bytearray.data))
-    delitem_slice_helper(space, w_bytearray.data, start, step, slicelength)
+    _delitem_slice_helper(space, w_bytearray.data, start, step, slicelength)
 
-# create new helper functions with different list type specialisation
-delitem_slice_helper = func_with_new_name(_delitem_slice_helper,
-                                          'delitem_slice_helper')
-setitem_slice_helper = func_with_new_name(_setitem_slice_helper,
-                                          'setitem_slice_helper')
+#XXX share the code again with the stuff in listobject.py
+def _delitem_slice_helper(space, items, start, step, slicelength):
+    if slicelength==0:
+        return
+
+    if step < 0:
+        start = start + step * (slicelength-1)
+        step = -step
+
+    if step == 1:
+        assert start >= 0
+        assert slicelength >= 0
+        del items[start:start+slicelength]
+    else:
+        n = len(items)
+        i = start
+
+        for discard in range(1, slicelength):
+            j = i+1
+            i += step
+            while j < i:
+                items[j-discard] = items[j]
+                j += 1
+
+        j = i+1
+        while j < n:
+            items[j-slicelength] = items[j]
+            j += 1
+        start = n - slicelength
+        assert start >= 0 # annotator hint
+        del items[start:]
+
+def _setitem_slice_helper(space, items, start, step, slicelength, sequence2,
+                          empty_elem):
+    assert slicelength >= 0
+    oldsize = len(items)
+    len2 = len(sequence2)
+    if step == 1:  # Support list resizing for non-extended slices
+        delta = slicelength - len2
+        if delta < 0:
+            delta = -delta
+            newsize = oldsize + delta
+            # XXX support this in rlist!
+            items += [empty_elem] * delta
+            lim = start+len2
+            i = newsize - 1
+            while i >= lim:
+                items[i] = items[i-delta]
+                i -= 1
+        elif start >= 0:
+            del items[start:start+delta]
+        else:
+            assert delta==0   # start<0 is only possible with slicelength==0
+    elif len2 != slicelength:  # No resize for extended slices
+        raise operationerrfmt(space.w_ValueError, "attempt to "
+              "assign sequence of size %d to extended slice of size %d",
+              len2, slicelength)
+
+    if sequence2 is items:
+        if step > 0:
+            # Always copy starting from the right to avoid
+            # having to make a shallow copy in the case where
+            # the source and destination lists are the same list.
+            i = len2 - 1
+            start += i*step
+            while i >= 0:
+                items[start] = sequence2[i]
+                start -= step
+                i -= 1
+            return
+        else:
+            # Make a shallow copy to more easily handle the reversal case
+            sequence2 = list(sequence2)
+    for i in range(len2):
+        items[start] = sequence2[i]
+        start += step
 
 def _strip(space, w_bytearray, u_chars, left, right):
     # note: mostly copied from stringobject._strip
diff --git a/pypy/objspace/std/celldict.py b/pypy/objspace/std/celldict.py
--- a/pypy/objspace/std/celldict.py
+++ b/pypy/objspace/std/celldict.py
@@ -65,11 +65,11 @@
         if isinstance(cell, ModuleCell):
             cell.w_value = w_value
             return
-        # If the new value and the current value are the same, don't create a
-        # level of indirection, or mutate are version.
-        if self.space.is_w(w_value, cell):
-            return
         if cell is not None:
+            # If the new value and the current value are the same, don't create a
+            # level of indirection, or mutate the version.
+            if self.space.is_w(w_value, cell):
+                return
             w_value = ModuleCell(w_value)
         self.mutated()
         self.unerase(w_dict.dstorage)[key] = w_value
diff --git a/pypy/objspace/std/frame.py b/pypy/objspace/std/frame.py
--- a/pypy/objspace/std/frame.py
+++ b/pypy/objspace/std/frame.py
@@ -58,7 +58,7 @@
     w_1 = f.popvalue()
     if type(w_1) is W_ListObject and type(w_2) is intobject.W_IntObject:
         try:
-            w_result = w_1.wrappeditems[w_2.intval]
+            w_result = w_1.getitem(w_2.intval)
         except IndexError:
             raise OperationError(f.space.w_IndexError,
                 f.space.wrap("list index out of range"))
diff --git a/pypy/objspace/std/iterobject.py b/pypy/objspace/std/iterobject.py
--- a/pypy/objspace/std/iterobject.py
+++ b/pypy/objspace/std/iterobject.py
@@ -33,9 +33,9 @@
     """Sequence iterator specialized for lists, accessing
     directly their RPython-level list of wrapped objects.
     """
-    def __init__(w_self, w_seq, wrappeditems):
+    def __init__(w_self, w_seq):
         W_AbstractSeqIterObject.__init__(w_self, w_seq)
-        w_self.listitems = wrappeditems
+        w_self.w_seq = w_seq
 
 class W_FastTupleIterObject(W_AbstractSeqIterObject):
    """Sequence iterator specialized for tuples, accessing
@@ -105,13 +105,15 @@
     return w_seqiter
 
 def next__FastListIter(space, w_seqiter):
-    if w_seqiter.listitems is None:
+    from pypy.objspace.std.listobject import W_ListObject
+    w_seq = w_seqiter.w_seq
+    if w_seq is None:
         raise OperationError(space.w_StopIteration, space.w_None)
+    assert isinstance(w_seq, W_ListObject)
     index = w_seqiter.index
     try:
-        w_item = w_seqiter.listitems[index]
+        w_item = w_seq.getitem(index)
     except IndexError:
-        w_seqiter.listitems = None
         w_seqiter.w_seq = None
         raise OperationError(space.w_StopIteration, space.w_None) 
     w_seqiter.index = index + 1
diff --git a/pypy/objspace/std/listobject.py b/pypy/objspace/std/listobject.py
--- a/pypy/objspace/std/listobject.py
+++ b/pypy/objspace/std/listobject.py
@@ -5,35 +5,937 @@
 from pypy.objspace.std.inttype import wrapint
 from pypy.objspace.std.listtype import get_list_index
 from pypy.objspace.std.sliceobject import W_SliceObject, normalize_simple_slice
-
 from pypy.objspace.std import slicetype
 from pypy.interpreter import gateway, baseobjspace
+from pypy.rlib.objectmodel import instantiate, specialize
 from pypy.rlib.listsort import make_timsort_class
+from pypy.rlib import rerased, jit
 from pypy.interpreter.argument import Signature
 
+UNROLL_CUTOFF = 5
+
 class W_AbstractListObject(W_Object):
     __slots__ = ()
 
+def make_range_list(space, start, step, length):
+    if length <= 0:
+        strategy = space.fromcache(EmptyListStrategy)
+        storage = strategy.erase(None)
+    else:
+        strategy = space.fromcache(RangeListStrategy)
+        storage = strategy.erase((start, step, length))
+    return W_ListObject.from_storage_and_strategy(space, storage, strategy)
+
+def make_empty_list(space):
+    strategy = space.fromcache(EmptyListStrategy)
+    storage = strategy.erase(None)
+    return W_ListObject.from_storage_and_strategy(space, storage, strategy)
+
+ at jit.look_inside_iff(lambda space, list_w: jit.isconstant(len(list_w)) and len(list_w) < UNROLL_CUTOFF)
+def get_strategy_from_list_objects(space, list_w):
+    if not list_w:
+        return space.fromcache(EmptyListStrategy)
+
+    # check for ints
+    for w_obj in list_w:
+        if not is_W_IntObject(w_obj):
+            break
+    else:
+        return space.fromcache(IntegerListStrategy)
+
+    # check for strings
+    for w_obj in list_w:
+        if not is_W_StringObject(w_obj):
+            break
+    else:
+        return space.fromcache(StringListStrategy)
+
+    return space.fromcache(ObjectListStrategy)
+
+def is_W_IntObject(w_object):
+    from pypy.objspace.std.intobject import W_IntObject
+    return type(w_object) is W_IntObject
+
+def is_W_StringObject(w_object):
+    from pypy.objspace.std.stringobject import W_StringObject
+    return type(w_object) is W_StringObject
+
+
+
 class W_ListObject(W_AbstractListObject):
     from pypy.objspace.std.listtype import list_typedef as typedef
 
-    def __init__(w_self, wrappeditems):
-        w_self.wrappeditems = wrappeditems
+    def __init__(w_self, space, wrappeditems):
+        assert isinstance(wrappeditems, list)
+        w_self.space = space
+        if space.config.objspace.std.withliststrategies:
+            w_self.strategy = get_strategy_from_list_objects(space, wrappeditems)
+        else:
+            w_self.strategy = space.fromcache(ObjectListStrategy)
+        w_self.init_from_list_w(wrappeditems)
+
+    @staticmethod
+    def from_storage_and_strategy(space, storage, strategy):
+        w_self = instantiate(W_ListObject)
+        w_self.space = space
+        w_self.strategy = strategy
+        w_self.lstorage = storage
+        if not space.config.objspace.std.withliststrategies:
+            w_self.switch_to_object_strategy()
+        return w_self
+
+    @staticmethod
+    def newlist_str(space, list_s):
+        strategy = space.fromcache(StringListStrategy)
+        storage = strategy.erase(list_s)
+        return W_ListObject.from_storage_and_strategy(space, storage, strategy)
 
     def __repr__(w_self):
         """ representation for debugging purposes """
-        return "%s(%s)" % (w_self.__class__.__name__, w_self.wrappeditems)
+        return "%s(%s, %s)" % (w_self.__class__.__name__, w_self.strategy, w_self.lstorage._x)
 
     def unwrap(w_list, space):
-        items = [space.unwrap(w_item) for w_item in w_list.wrappeditems]# XXX generic mixed types unwrap
+        # for tests only!
+        items = [space.unwrap(w_item) for w_item in w_list.getitems()]
         return list(items)
 
+    def switch_to_object_strategy(self):
+        list_w = self.getitems()
+        self.strategy = self.space.fromcache(ObjectListStrategy)
+        # XXX this is quite indirect
+        self.init_from_list_w(list_w)
+
+    def _temporarily_as_objects(self):
+        if self.strategy is self.space.fromcache(ObjectListStrategy):
+            return self
+        list_w = self.getitems()
+        strategy = self.space.fromcache(ObjectListStrategy)
+        storage = strategy.erase(list_w)
+        w_objectlist = W_ListObject.from_storage_and_strategy(self.space, storage, strategy)
+        return w_objectlist
+
+    # ___________________________________________________
+
+    def init_from_list_w(self, list_w):
+        """Initializes listobject by iterating through the given list of
+        wrapped items, unwrapping them if neccessary and creating a
+        new erased object as storage"""
+        self.strategy.init_from_list_w(self, list_w)
+
+    def clone(self):
+        """Returns a clone by creating a new listobject
+        with the same strategy and a copy of the storage"""
+        return self.strategy.clone(self)
+
+    def copy_into(self, other):
+        """Used only when extending an EmptyList. Sets the EmptyLists
+        strategy and storage according to the other W_List"""
+        self.strategy.copy_into(self, other)
+
+    def contains(self, w_obj):
+        """Returns unwrapped boolean, saying wether w_obj exists
+        in the list."""
+        return self.strategy.contains(self, w_obj)
+
     def append(w_list, w_item):
-        w_list.wrappeditems.append(w_item)
+        """Appends the wrapped item to the end of the list."""
+        w_list.strategy.append(w_list, w_item)
+
+    def length(self):
+        return self.strategy.length(self)
+
+    def getitem(self, index):
+        """Returns the wrapped object that is found in the
+        list at the given index. The index must be unwrapped.
+        May raise IndexError."""
+        return self.strategy.getitem(self, index)
+
+    def getslice(self, start, stop, step, length):
+        """Returns a slice of the list defined by the arguments. Arguments must be
+        normalized (i.e. using normalize_simple_slice or W_Slice.indices4).
+        May raise IndexError."""
+        return self.strategy.getslice(self, start, stop, step, length)
+
+    def getitems(self):
+        """Returns a list of all items after wrapping them. The result can
+        share with the storage, if possible."""
+        return self.strategy.getitems(self)
+
+    def getitems_copy(self):
+        """Returns a copy of all items in the list. Same as getitems except for
+        ObjectListStrategy."""
+        return self.strategy.getitems_copy(self)
+
+    def getitems_str(self):
+        """ Return the items in the list as unwrapped strings. If the list does
+        not use the list strategy, return None. """
+        return self.strategy.getitems_str(self)
+    # ___________________________________________________
+
+
+    def mul(self, times):
+        """Returns a copy of the list, multiplied by times.
+        Argument must be unwrapped."""
+        return self.strategy.mul(self, times)
+
+    def inplace_mul(self, times):
+        """Alters the list by multiplying its content by times."""
+        self.strategy.inplace_mul(self, times)
+
+    def deleteslice(self, start, step, length):
+        """Deletes a slice from the list. Used in delitem and delslice.
+        Arguments must be normalized (see getslice)."""
+        self.strategy.deleteslice(self, start, step, length)
+
+    def pop(self, index):
+        """Pops an item from the list. Index must be normalized.
+        May raise IndexError."""
+        return self.strategy.pop(self, index)
+
+    def pop_end(self):
+        """ Pop the last element from the list."""
+        return self.strategy.pop_end(self)
+
+    def setitem(self, index, w_item):
+        """Inserts a wrapped item at the given (unwrapped) index.
+        May raise IndexError."""
+        self.strategy.setitem(self, index, w_item)
+
+    def setslice(self, start, step, slicelength, sequence_w):
+        """Sets the slice of the list from start to start+step*slicelength to
+        the sequence sequence_w.
+        Used by setslice and setitem."""
+        self.strategy.setslice(self, start, step, slicelength, sequence_w)
+
+    def insert(self, index, w_item):
+        """Inserts an item at the given position. Item must be wrapped,
+        index not."""
+        self.strategy.insert(self, index, w_item)
+
+    def extend(self, items_w):
+        """Appends the given list of wrapped items."""
+        self.strategy.extend(self, items_w)
+
+    def reverse(self):
+        """Reverses the list."""
+        self.strategy.reverse(self)
+
+    def sort(self, reverse):
+        """Sorts the list ascending or descending depending on
+        argument reverse. Argument must be unwrapped."""
+        self.strategy.sort(self, reverse)
 
 registerimplementation(W_ListObject)
 
 
+class ListStrategy(object):
+
+    def __init__(self, space):
+        self.space = space
+
+    def init_from_list_w(self, w_list, list_w):
+        raise NotImplementedError
+
+    def clone(self, w_list):
+        raise NotImplementedError
+
+    def copy_into(self, w_list, w_other):
+        raise NotImplementedError
+
+    def contains(self, w_list, w_obj):
+        # needs to be safe against eq_w() mutating the w_list behind our back
+        i = 0
+        while i < w_list.length(): # intentionally always calling len!
+            if self.space.eq_w(w_list.getitem(i), w_obj):
+                return True
+            i += 1
+        return False
+
+    def length(self, w_list):
+        raise NotImplementedError
+
+    def getitem(self, w_list, index):
+        raise NotImplementedError
+
+    def getslice(self, w_list, start, stop, step, length):
+        raise NotImplementedError
+
+    def getitems(self, w_list):
+        return self.getitems_copy(w_list)
+
+    def getitems_copy(self, w_list):
+        raise NotImplementedError
+
+    def getitems_str(self, w_list):
+        return None
+
+    def getstorage_copy(self, w_list):
+        raise NotImplementedError
+
+    def append(self, w_list, w_item):
+        raise NotImplementedError
+
+    def mul(self, w_list, times):
+        w_newlist = w_list.clone()
+        w_newlist.inplace_mul(times)
+        return w_newlist
+
+    def inplace_mul(self, w_list, times):
+        raise NotImplementedError
+
+    def deleteslice(self, w_list, start, step, slicelength):
+        raise NotImplementedError
+
+    def pop(self, w_list, index):
+        raise NotImplementedError
+
+    def pop_end(self, w_list):
+        return self.pop(w_list, self.length(w_list) - 1)
+
+    def setitem(self, w_list, index, w_item):
+        raise NotImplementedError
+
+    def setslice(self, w_list, start, step, slicelength, sequence_w):
+        raise NotImplementedError
+
+    def insert(self, w_list, index, w_item):
+        raise NotImplementedError
+
+    def extend(self, w_list, items_w):
+        raise NotImplementedError
+
+    def reverse(self, w_list):
+        raise NotImplementedError
+
+    def sort(self, w_list, reverse):
+        raise NotImplementedError
+
+class EmptyListStrategy(ListStrategy):
+    """EmptyListStrategy is used when a W_List withouth elements is created.
+    The storage is None. When items are added to the W_List a new RPython list
+    is created and the strategy and storage of the W_List are changed depending
+    to the added item.
+    W_Lists do not switch back to EmptyListStrategy when becoming empty again."""
+
+    def __init__(self, space):
+        ListStrategy.__init__(self, space)
+        # cache an empty list that is used whenever getitems is called (i.e. sorting)
+        self.cached_emptylist_w = []
+
+    def init_from_list_w(self, w_list, list_w):
+        assert len(list_w) == 0
+        w_list.lstorage = self.erase(None)
+
+    erase, unerase = rerased.new_erasing_pair("empty")
+    erase = staticmethod(erase)
+    unerase = staticmethod(unerase)
+
+    def clone(self, w_list):
+        return W_ListObject.from_storage_and_strategy(self.space, w_list.lstorage, self)
+
+    def copy_into(self, w_list, w_other):
+        pass
+
+    def contains(self, w_list, w_obj):
+        return False
+
+    def length(self, w_list):
+        return 0
+
+    def getitem(self, w_list, index):
+        raise IndexError
+
+    def getslice(self, w_list, start, stop, step, length):
+        # will never be called because the empty list case is already caught in
+        # getslice__List_ANY_ANY and getitem__List_Slice
+        return W_ListObject(self.space, self.cached_emptylist_w)
+
+    def getitems(self, w_list):
+        return self.cached_emptylist_w
+
+    def getitems_copy(self, w_list):
+        return []
+
+    def getstorage_copy(self, w_list):
+        return self.erase(None)
+
+    def switch_to_correct_strategy(self, w_list, w_item):
+        if is_W_IntObject(w_item):
+            strategy = self.space.fromcache(IntegerListStrategy)
+        elif is_W_StringObject(w_item):
+            strategy = self.space.fromcache(StringListStrategy)
+        else:
+            strategy = self.space.fromcache(ObjectListStrategy)
+
+        storage = strategy.get_empty_storage()
+        w_list.strategy = strategy
+        w_list.lstorage = storage
+
+    def append(self, w_list, w_item):
+        self.switch_to_correct_strategy(w_list, w_item)
+        w_list.append(w_item)
+
+    def inplace_mul(self, w_list, times):
+        return
+
+    def deleteslice(self, w_list, start, step, slicelength):
+        pass
+
+    def pop(self, w_list, index):
+        # will not be called because IndexError was already raised in
+        # list_pop__List_ANY
+        raise IndexError
+
+    def setitem(self, w_list, index, w_item):
+        raise IndexError
+
+    def setslice(self, w_list, start, step, slicelength, w_other):
+        strategy = w_other.strategy
+        storage = strategy.getstorage_copy(w_other)
+        w_list.strategy = strategy
+        w_list.lstorage = storage
+
+    def sort(self, w_list, reverse):
+        return
+
+    def insert(self, w_list, index, w_item):
+        assert index == 0
+        self.append(w_list, w_item)
+
+    def extend(self, w_list, w_other):
+        w_other.copy_into(w_list)
+
+    def reverse(self, w_list):
+        pass
+
+class RangeListStrategy(ListStrategy):
+    """RangeListStrategy is used when a list is created using the range method.
+    The storage is a tuple containing only three integers start, step and length
+    and elements are calculated based on these values.
+    On any operation destroying the range (inserting, appending non-ints)
+    the strategy is switched to IntegerListStrategy."""
+
+    def switch_to_integer_strategy(self, w_list):
+        items = self._getitems_range(w_list, False)
+        strategy = w_list.strategy = self.space.fromcache(IntegerListStrategy)
+        w_list.lstorage = strategy.erase(items)
+
+    def wrap(self, intval):
+        return self.space.wrap(intval)
+
+    def unwrap(self, w_int):
+        return self.space.int_w(w_int)
+
+    def init_from_list_w(self, w_list, list_w):
+        raise NotImplementedError
+
+    erase, unerase = rerased.new_erasing_pair("range")
+    erase = staticmethod(erase)
+    unerase = staticmethod(unerase)
+
+    def clone(self, w_list):
+        storage = w_list.lstorage # lstorage is tuple, no need to clone
+        w_clone = W_ListObject.from_storage_and_strategy(self.space, storage, self)
+        return w_clone
+
+    def copy_into(self, w_list, w_other):
+        w_other.strategy = self
+        w_other.lstorage = w_list.lstorage
+
+    def contains(self, w_list, w_obj):
+        if is_W_IntObject(w_obj):
+            start, step, length = self.unerase(w_list.lstorage)
+            obj = self.unwrap(w_obj)
+            i = start
+            if step > 0 and start <= obj <= start + (length - 1) * step and (start - obj) % step == 0:
+                return True
+            elif step < 0 and start + (length -1) * step <= obj <= start and (start - obj) % step == 0:
+                return True
+            else:
+                return False
+        return ListStrategy.contains(self, w_list, w_obj)
+
+    def length(self, w_list):
+        return self.unerase(w_list.lstorage)[2]
+
+    def _getitem_unwrapped(self, w_list, i):
+        v = self.unerase(w_list.lstorage)
+        start = v[0]
+        step = v[1]
+        length = v[2]
+        if i < 0:
+            i += length
+            if i < 0:
+                raise IndexError
+        elif i >= length:
+            raise IndexError
+        return start + i * step
+
+    def getitem(self, w_list, i):
+        return self.wrap(self._getitem_unwrapped(w_list, i))
+
+    def getitems_copy(self, w_list):
+        return self._getitems_range(w_list, True)
+
+    def getstorage_copy(self, w_list):
+        # tuple is unmutable
+        return w_list.lstorage
+
+
+    @specialize.arg(2)
+    def _getitems_range(self, w_list, wrap_items):
+        l = self.unerase(w_list.lstorage)
+        start = l[0]
+        step = l[1]
+        length  = l[2]
+        if wrap_items:
+            r = [None] * length
+        else:
+            r = [0] * length
+        i = start
+        n = 0
+        while n < length:
+            if wrap_items:
+                r[n] = self.wrap(i)
+            else:
+                r[n] = i
+            i += step
+            n += 1
+
+        return r
+
+    def getslice(self, w_list, start, stop, step, length):
+        v = self.unerase(w_list.lstorage)
+        old_start = v[0]
+        old_step = v[1]
+        old_length = v[2]
+
+        new_start = self._getitem_unwrapped(w_list, start)
+        new_step = old_step * step
+        return make_range_list(self.space, new_start, new_step, length)
+
+    def append(self, w_list, w_item):
+        if is_W_IntObject(w_item):
+            l = self.unerase(w_list.lstorage)
+            step = l[1]
+            last_in_range = self._getitem_unwrapped(w_list, -1)
+            if self.unwrap(w_item) - step == last_in_range:
+                new = self.erase((l[0],l[1],l[2]+1))
+                w_list.lstorage = new
+                return
+
+            self.switch_to_integer_strategy(w_list)
+        else:
+            w_list.switch_to_object_strategy()
+        w_list.append(w_item)
+
+    def inplace_mul(self, w_list, times):
+        self.switch_to_integer_strategy(w_list)
+        w_list.inplace_mul(times)
+
+    def deleteslice(self, w_list, start, step, slicelength):
+        self.switch_to_integer_strategy(w_list)
+        w_list.deleteslice(start, step, slicelength)
+
+    def pop_end(self, w_list):
+        start, step, length = self.unerase(w_list.lstorage)
+        w_result = self.wrap(start + (length - 1) * step)
+        new = self.erase((start, step, length - 1))
+        w_list.lstorage = new
+        return w_result
+
+    def pop(self, w_list, index):
+        l = self.unerase(w_list.lstorage)
+        start = l[0]
+        step = l[1]
+        length = l[2]
+        if index == 0:
+            w_result = self.wrap(start)
+            new = self.erase((start + step, step, length - 1))
+            w_list.lstorage = new
+            return w_result
+        elif index == length - 1:
+            return self.pop_end(w_list)
+        else:
+            self.switch_to_integer_strategy(w_list)
+            return w_list.pop(index)
+
+    def setitem(self, w_list, index, w_item):
+        self.switch_to_integer_strategy(w_list)
+        w_list.setitem(index, w_item)
+
+    def setslice(self, w_list, start, step, slicelength, sequence_w):
+        self.switch_to_integer_strategy(w_list)
+        w_list.setslice(start, step, slicelength, sequence_w)
+
+    def sort(self, w_list, reverse):
+        start, step, length = self.unerase(w_list.lstorage)
+        if step > 0 and reverse or step < 0 and not reverse:
+            start = start + step * (length - 1)
+            step = step * (-1)
+        else:
+            return
+        w_list.lstorage = self.erase((start, step, length))
+
+    def insert(self, w_list, index, w_item):
+        self.switch_to_integer_strategy(w_list)
+        w_list.insert(index, w_item)
+
+    def extend(self, w_list, items_w):
+        self.switch_to_integer_strategy(w_list)
+        w_list.extend(items_w)
+
+    def reverse(self, w_list):
+        v = self.unerase(w_list.lstorage)
+        last = self._getitem_unwrapped(w_list, -1)
+        length = v[2]
+        skip = v[1]
+        new = self.erase((last, -skip, length))
+        w_list.lstorage = new
+
+class AbstractUnwrappedStrategy(object):
+    _mixin_ = True
+
+    def wrap(self, unwrapped):
+        raise NotImplementedError
+
+    def unwrap(self, wrapped):
+        raise NotImplementedError
+
+    @staticmethod
+    def unerase(storage):
+        raise NotImplementedError("abstract base class")
+
+    @staticmethod
+    def erase(obj):
+        raise NotImplementedError("abstract base class")
+
+    def is_correct_type(self, w_obj):
+        raise NotImplementedError("abstract base class")
+
+    def list_is_correct_type(self, w_list):
+        raise NotImplementedError("abstract base class")
+
+    @jit.look_inside_iff(lambda space, w_list, list_w:
+        jit.isconstant(len(list_w)) and len(list_w) < UNROLL_CUTOFF)
+    def init_from_list_w(self, w_list, list_w):
+        l = [self.unwrap(w_item) for w_item in list_w]
+        w_list.lstorage = self.erase(l)
+
+    def get_empty_storage(self):
+        return self.erase([])
+
+    def clone(self, w_list):
+        l = self.unerase(w_list.lstorage)
+        storage = self.erase(l[:])
+        w_clone = W_ListObject.from_storage_and_strategy(self.space, storage, self)
+        return w_clone
+
+    def copy_into(self, w_list, w_other):
+        w_other.strategy = self
+        items = self.unerase(w_list.lstorage)[:]
+        w_other.lstorage = self.erase(items)
+
+    def contains(self, w_list, w_obj):
+        if self.is_correct_type(w_obj):
+            obj = self.unwrap(w_obj)
+            l = self.unerase(w_list.lstorage)
+            for i in l:
+                if i == obj:
+                    return True
+        return ListStrategy.contains(self, w_list, w_obj)
+
+    def length(self, w_list):
+        return len(self.unerase(w_list.lstorage))
+
+    def getitem(self, w_list, index):
+        l = self.unerase(w_list.lstorage)
+        try:
+            r = l[index]
+        except IndexError: # make RPython raise the exception
+            raise
+        return self.wrap(r)
+
+    @jit.look_inside_iff(lambda self, w_list:
+            jit.isconstant(w_list.length()) and w_list.length() < UNROLL_CUTOFF)
+    def getitems_copy(self, w_list):
+        return [self.wrap(item) for item in self.unerase(w_list.lstorage)]
+
+    def getstorage_copy(self, w_list):
+        items = self.unerase(w_list.lstorage)[:]
+        return self.erase(items)
+
+
+    def getslice(self, w_list, start, stop, step, length):
+        if step == 1 and 0 <= start <= stop:
+            l = self.unerase(w_list.lstorage)
+            assert start >= 0
+            assert stop >= 0
+            sublist = l[start:stop]
+            storage = self.erase(sublist)
+            return W_ListObject.from_storage_and_strategy(self.space, storage, self)
+        else:
+            subitems_w = [self._none_value] * length
+            l = self.unerase(w_list.lstorage)
+            for i in range(length):
+                try:
+                    subitems_w[i] = l[start]
+                    start += step
+                except IndexError:
+                    raise
+            storage = self.erase(subitems_w)
+            return W_ListObject.from_storage_and_strategy(self.space, storage, self)
+
+    def append(self,  w_list, w_item):
+
+        if self.is_correct_type(w_item):
+            self.unerase(w_list.lstorage).append(self.unwrap(w_item))
+            return
+
+        w_list.switch_to_object_strategy()
+        w_list.append(w_item)
+
+    def insert(self, w_list, index, w_item):
+        l = self.unerase(w_list.lstorage)
+
+        if self.is_correct_type(w_item):
+            l.insert(index, self.unwrap(w_item))
+            return
+
+        w_list.switch_to_object_strategy()
+        w_list.insert(index, w_item)
+
+    def extend(self, w_list, w_other):
+        l = self.unerase(w_list.lstorage)
+        if self.list_is_correct_type(w_other):
+            l += self.unerase(w_other.lstorage)
+            return
+        elif w_other.strategy is self.space.fromcache(EmptyListStrategy):
+            return
+
+        w_other = w_other._temporarily_as_objects()
+        w_list.switch_to_object_strategy()
+        w_list.extend(w_other)
+
+    def setitem(self, w_list, index, w_item):
+        l = self.unerase(w_list.lstorage)
+
+        if self.is_correct_type(w_item):
+            try:
+                l[index] = self.unwrap(w_item)
+            except IndexError:
+                raise
+            return
+
+        w_list.switch_to_object_strategy()
+        w_list.setitem(index, w_item)
+
+    def setslice(self, w_list, start, step, slicelength, w_other):
+        assert slicelength >= 0
+        items = self.unerase(w_list.lstorage)
+
+        if self is self.space.fromcache(ObjectListStrategy):
+            w_other = w_other._temporarily_as_objects()
+        elif (not self.list_is_correct_type(w_other) and
+               w_other.length() != 0):
+            w_list.switch_to_object_strategy()
+            w_other_as_object = w_other._temporarily_as_objects()
+            assert w_other_as_object.strategy is self.space.fromcache(ObjectListStrategy)
+            w_list.setslice(start, step, slicelength, w_other_as_object)
+            return
+
+        oldsize = len(items)
+        len2 = w_other.length()
+        if step == 1:  # Support list resizing for non-extended slices
+            delta = slicelength - len2
+            if delta < 0:
+                delta = -delta
+                newsize = oldsize + delta
+                # XXX support this in rlist!
+                items += [self._none_value] * delta
+                lim = start+len2
+                i = newsize - 1
+                while i >= lim:
+                    items[i] = items[i-delta]
+                    i -= 1
+            elif start >= 0:
+                del items[start:start+delta]
+            else:
+                assert delta==0   # start<0 is only possible with slicelength==0
+        elif len2 != slicelength:  # No resize for extended slices
+            raise operationerrfmt(self.space.w_ValueError, "attempt to "
+                  "assign sequence of size %d to extended slice of size %d",
+                  len2, slicelength)
+
+        if w_other.strategy is self.space.fromcache(EmptyListStrategy):
+            other_items = []
+        else:
+            # at this point both w_list and w_other have the same type, so
+            # self.unerase is valid for both of them
+            other_items = self.unerase(w_other.lstorage)
+        if other_items is items:
+            if step > 0:
+                # Always copy starting from the right to avoid
+                # having to make a shallow copy in the case where
+                # the source and destination lists are the same list.
+                i = len2 - 1
+                start += i*step
+                while i >= 0:
+                    items[start] = other_items[i]
+                    start -= step
+                    i -= 1
+                return
+            else:
+                # Make a shallow copy to more easily handle the reversal case
+                w_list.reverse()
+                return
+                #other_items = list(other_items)
+        for i in range(len2):
+            items[start] = other_items[i]
+            start += step
+
+    def deleteslice(self, w_list, start, step, slicelength):
+        items = self.unerase(w_list.lstorage)
+        if slicelength==0:
+            return
+
+        if step < 0:
+            start = start + step * (slicelength-1)
+            step = -step
+
+        if step == 1:
+            assert start >= 0
+            assert slicelength >= 0
+            del items[start:start+slicelength]
+        else:
+            n = len(items)
+            i = start
+
+            for discard in range(1, slicelength):
+                j = i+1
+                i += step
+                while j < i:
+                    items[j-discard] = items[j]
+                    j += 1
+
+            j = i+1
+            while j < n:
+                items[j-slicelength] = items[j]
+                j += 1
+            start = n - slicelength
+            assert start >= 0 # annotator hint
+            del items[start:]
+
+    def pop_end(self, w_list):
+        l = self.unerase(w_list.lstorage)
+        return self.wrap(l.pop())
+
+    def pop(self, w_list, index):
+        l = self.unerase(w_list.lstorage)
+        # not sure if RPython raises IndexError on pop
+        # so check again here
+        if index < 0:
+            raise IndexError
+        try:
+            item = l.pop(index)
+        except IndexError:
+            raise
+
+        w_item = self.wrap(item)
+        return w_item
+
+    def inplace_mul(self, w_list, times):
+        l = self.unerase(w_list.lstorage)
+        l *= times
+
+    def reverse(self, w_list):
+        self.unerase(w_list.lstorage).reverse()
+
+class ObjectListStrategy(AbstractUnwrappedStrategy, ListStrategy):
+    _none_value = None
+
+    def unwrap(self, w_obj):
+        return w_obj
+
+    def wrap(self, item):
+        return item
+
+    erase, unerase = rerased.new_erasing_pair("object")
+    erase = staticmethod(erase)
+    unerase = staticmethod(unerase)
+
+    def is_correct_type(self, w_obj):
+        return True
+
+    def list_is_correct_type(self, w_list):
+        return w_list.strategy is self.space.fromcache(ObjectListStrategy)
+
+    def init_from_list_w(self, w_list, list_w):
+        w_list.lstorage = self.erase(list_w)
+
+    def contains(self, w_list, w_obj):
+        return ListStrategy.contains(self, w_list, w_obj)
+
+    def getitems(self, w_list):
+        return self.unerase(w_list.lstorage)
+
+class IntegerListStrategy(AbstractUnwrappedStrategy, ListStrategy):
+    _none_value = 0
+
+    def wrap(self, intval):
+        return self.space.wrap(intval)
+
+    def unwrap(self, w_int):
+        return self.space.int_w(w_int)
+
+    erase, unerase = rerased.new_erasing_pair("integer")
+    erase = staticmethod(erase)
+    unerase = staticmethod(unerase)
+
+    def is_correct_type(self, w_obj):
+        return is_W_IntObject(w_obj)
+
+    def list_is_correct_type(self, w_list):
+        return w_list.strategy is self.space.fromcache(IntegerListStrategy)
+
+    def sort(self, w_list, reverse):
+        l = self.unerase(w_list.lstorage)
+        sorter = IntSort(l, len(l))
+        sorter.sort()
+        if reverse:
+            l.reverse()
+
+class StringListStrategy(AbstractUnwrappedStrategy, ListStrategy):
+    _none_value = None
+
+    def wrap(self, stringval):
+        return self.space.wrap(stringval)
+
+    def unwrap(self, w_string):
+        return self.space.str_w(w_string)
+
+    erase, unerase = rerased.new_erasing_pair("string")
+    erase = staticmethod(erase)
+    unerase = staticmethod(unerase)
+
+    def is_correct_type(self, w_obj):
+        return is_W_StringObject(w_obj)
+
+    def list_is_correct_type(self, w_list):
+        return w_list.strategy is self.space.fromcache(StringListStrategy)
+
+    def sort(self, w_list, reverse):
+        l = self.unerase(w_list.lstorage)
+        sorter = StringSort(l, len(l))
+        sorter.sort()
+        if reverse:
+            l.reverse()
+
+    def getitems_str(self, w_list):
+        return self.unerase(w_list.lstorage)
+
+# _______________________________________________________
+
 init_signature = Signature(['sequence'], None, None)
 init_defaults = [None]
 
@@ -42,25 +944,24 @@
     # this is on the silly side
     w_iterable, = __args__.parse_obj(
             None, 'list', init_signature, init_defaults)
-    items_w = w_list.wrappeditems
-    del items_w[:]
+    w_list.__init__(space, [])
     if w_iterable is not None:
         # unfortunately this is duplicating space.unpackiterable to avoid
         # assigning a new RPython list to 'wrappeditems', which defeats the
         # W_FastListIterObject optimization.
         if isinstance(w_iterable, W_ListObject):
-            items_w.extend(w_iterable.wrappeditems)
+            w_list.extend(w_iterable)
         elif isinstance(w_iterable, W_TupleObject):
-            items_w.extend(w_iterable.wrappeditems)
+            w_list.extend(W_ListObject(space, w_iterable.wrappeditems[:]))
         else:
-            _init_from_iterable(space, items_w, w_iterable)
+            _init_from_iterable(space, w_list, w_iterable)
 
-def _init_from_iterable(space, items_w, w_iterable):
+def _init_from_iterable(space, w_list, w_iterable):
     # in its own function to make the JIT look into init__List
     # xxx special hack for speed
     from pypy.interpreter.generator import GeneratorIterator
     if isinstance(w_iterable, GeneratorIterator):
-        w_iterable.unpack_into(items_w)
+        w_iterable.unpack_into_w(w_list)
         return
     # /xxx
     w_iterator = space.iter(w_iterable)
@@ -71,70 +972,65 @@
             if not e.match(space, space.w_StopIteration):
                 raise
             break  # done
-        items_w.append(w_item)
+        w_list.append(w_item)
 
 def len__List(space, w_list):
-    result = len(w_list.wrappeditems)
+    result = w_list.length()
     return wrapint(space, result)
 
 def getitem__List_ANY(space, w_list, w_index):
     try:
-        return w_list.wrappeditems[get_list_index(space, w_index)]
+        return w_list.getitem(get_list_index(space, w_index))
     except IndexError:
         raise OperationError(space.w_IndexError,
                              space.wrap("list index out of range"))
 
 def getitem__List_Slice(space, w_list, w_slice):
     # XXX consider to extend rlist's functionality?
-    length = len(w_list.wrappeditems)
+    length = w_list.length()
     start, stop, step, slicelength = w_slice.indices4(space, length)
     assert slicelength >= 0
-    if step == 1 and 0 <= start <= stop:
-        return W_ListObject(w_list.wrappeditems[start:stop])
-    w_res = W_ListObject([None] * slicelength)
-    items_w = w_list.wrappeditems
-    subitems_w = w_res.wrappeditems
-    for i in range(slicelength):
-        subitems_w[i] = items_w[start]
-        start += step
-    return w_res
+    if slicelength == 0:
+        return make_empty_list(space)
+    return w_list.getslice(start, stop, step, slicelength)
 
 def getslice__List_ANY_ANY(space, w_list, w_start, w_stop):
-    length = len(w_list.wrappeditems)
-    start, stop = normalize_simple_slice(space, length, w_start, w_stop)
-    return W_ListObject(w_list.wrappeditems[start:stop])
-
-def setslice__List_ANY_ANY_ANY(space, w_list, w_start, w_stop, w_sequence):
-    length = len(w_list.wrappeditems)
+    length = w_list.length()
     start, stop = normalize_simple_slice(space, length, w_start, w_stop)
 
-    sequence2 = space.listview(w_sequence)
-    items = w_list.wrappeditems
-    _setitem_slice_helper(space, items, start, 1, stop-start, sequence2,
-                          empty_elem=None)
+    slicelength = stop - start
+    if slicelength == 0:
+        return make_empty_list(space)
+    return w_list.getslice(start, stop, 1, stop - start)
+
+def setslice__List_ANY_ANY_List(space, w_list, w_start, w_stop, w_other):
+    length = w_list.length()
+    start, stop = normalize_simple_slice(space, length, w_start, w_stop)
+    w_list.setslice(start, 1, stop-start, w_other)
+
+def setslice__List_ANY_ANY_ANY(space, w_list, w_start, w_stop, w_iterable):
+    length = w_list.length()
+    start, stop = normalize_simple_slice(space, length, w_start, w_stop)
+    sequence_w = space.listview(w_iterable)
+    w_other = W_ListObject(space, sequence_w)
+    w_list.setslice(start, 1, stop-start, w_other)
 
 def delslice__List_ANY_ANY(space, w_list, w_start, w_stop):
-    length = len(w_list.wrappeditems)
+    length = w_list.length()
     start, stop = normalize_simple_slice(space, length, w_start, w_stop)
-    _delitem_slice_helper(space, w_list.wrappeditems, start, 1, stop-start)
+    w_list.deleteslice(start, 1, stop-start)
 
 def contains__List_ANY(space, w_list, w_obj):
-    # needs to be safe against eq_w() mutating the w_list behind our back
-    i = 0
-    items_w = w_list.wrappeditems
-    while i < len(items_w): # intentionally always calling len!
-        if space.eq_w(items_w[i], w_obj):
-            return space.w_True
-        i += 1
-    return space.w_False
+    return space.wrap(w_list.contains(w_obj))
 
 def iter__List(space, w_list):
     from pypy.objspace.std import iterobject
-    return iterobject.W_FastListIterObject(w_list, w_list.wrappeditems)
+    return iterobject.W_FastListIterObject(w_list)
 
 def add__List_List(space, w_list1, w_list2):
-    return W_ListObject(w_list1.wrappeditems + w_list2.wrappeditems)
-
+    w_clone = w_list1.clone()
+    w_clone.extend(w_list2)
+    return w_clone
 
 def inplace_add__List_ANY(space, w_list1, w_iterable2):
     try:
@@ -156,7 +1052,7 @@
         if e.match(space, space.w_TypeError):
             raise FailedToImplement
         raise
-    return W_ListObject(w_list.wrappeditems * times)
+    return w_list.mul(times)
 
 def mul__List_ANY(space, w_list, w_times):
     return mul_list_times(space, w_list, w_times)
@@ -171,63 +1067,65 @@
         if e.match(space, space.w_TypeError):
             raise FailedToImplement
         raise
-    w_list.wrappeditems *= times
+    w_list.inplace_mul(times)
     return w_list
 
 def eq__List_List(space, w_list1, w_list2):
     # needs to be safe against eq_w() mutating the w_lists behind our back
-    items1_w = w_list1.wrappeditems
-    items2_w = w_list2.wrappeditems
-    return equal_wrappeditems(space, items1_w, items2_w)
+    if w_list1.length() != w_list2.length():
+        return space.w_False
 
-def equal_wrappeditems(space, items1_w, items2_w):
-    if len(items1_w) != len(items2_w):
-        return space.w_False
+    # XXX in theory, this can be implemented more efficiently as well. let's
+    # not care for now
     i = 0
-    while i < len(items1_w) and i < len(items2_w):
-        if not space.eq_w(items1_w[i], items2_w[i]):
+    while i < w_list1.length() and i < w_list2.length():
+        if not space.eq_w(w_list1.getitem(i), w_list2.getitem(i)):
             return space.w_False
         i += 1
     return space.w_True
 
-def lessthan_unwrappeditems(space, items1_w, items2_w):
+def lessthan_unwrappeditems(space, w_list1, w_list2):
     # needs to be safe against eq_w() mutating the w_lists behind our back
     # Search for the first index where items are different
     i = 0
-    while i < len(items1_w) and i < len(items2_w):
-        w_item1 = items1_w[i]
-        w_item2 = items2_w[i]
+    # XXX in theory, this can be implemented more efficiently as well. let's
+    # not care for now
+    while i < w_list1.length() and i < w_list2.length():
+        w_item1 = w_list1.getitem(i)
+        w_item2 = w_list2.getitem(i)
         if not space.eq_w(w_item1, w_item2):
             return space.lt(w_item1, w_item2)
         i += 1
     # No more items to compare -- compare sizes
-    return space.newbool(len(items1_w) < len(items2_w))
+    return space.newbool(w_list1.length() < w_list2.length())
 
-def greaterthan_unwrappeditems(space, items1_w, items2_w):
+def greaterthan_unwrappeditems(space, w_list1, w_list2):
     # needs to be safe against eq_w() mutating the w_lists behind our back
     # Search for the first index where items are different
     i = 0
-    while i < len(items1_w) and i < len(items2_w):
-        w_item1 = items1_w[i]
-        w_item2 = items2_w[i]
+    # XXX in theory, this can be implemented more efficiently as well. let's
+    # not care for now
+    while i < w_list1.length() and i < w_list2.length():
+        w_item1 = w_list1.getitem(i)
+        w_item2 = w_list2.getitem(i)
         if not space.eq_w(w_item1, w_item2):
             return space.gt(w_item1, w_item2)
         i += 1
     # No more items to compare -- compare sizes
-    return space.newbool(len(items1_w) > len(items2_w))
+    return space.newbool(w_list1.length() > w_list2.length())
 
 def lt__List_List(space, w_list1, w_list2):
-    return lessthan_unwrappeditems(space, w_list1.wrappeditems,
-        w_list2.wrappeditems)
+    return lessthan_unwrappeditems(space, w_list1, w_list2)
 
 def gt__List_List(space, w_list1, w_list2):
-    return greaterthan_unwrappeditems(space, w_list1.wrappeditems,
-        w_list2.wrappeditems)
+    return greaterthan_unwrappeditems(space, w_list1, w_list2)
 
 def delitem__List_ANY(space, w_list, w_idx):
     idx = get_list_index(space, w_idx)
+    if idx < 0:
+        idx += w_list.length()
     try:
-        del w_list.wrappeditems[idx]
+        w_list.pop(idx)
     except IndexError:
         raise OperationError(space.w_IndexError,
                              space.wrap("list deletion index out of range"))
@@ -235,103 +1133,29 @@
 
 
 def delitem__List_Slice(space, w_list, w_slice):
-    start, stop, step, slicelength = w_slice.indices4(space,
-                                                      len(w_list.wrappeditems))
-    _delitem_slice_helper(space, w_list.wrappeditems, start, step, slicelength)
-
-def _delitem_slice_helper(space, items, start, step, slicelength):
-    if slicelength==0:
-        return
-
-    if step < 0:
-        start = start + step * (slicelength-1)
-        step = -step
-
-    if step == 1:
-        assert start >= 0
-        assert slicelength >= 0
-        del items[start:start+slicelength]
-    else:
-        n = len(items)
-        i = start
-
-        for discard in range(1, slicelength):
-            j = i+1
-            i += step
-            while j < i:
-                items[j-discard] = items[j]
-                j += 1
-
-        j = i+1
-        while j < n:
-            items[j-slicelength] = items[j]
-            j += 1
-        start = n - slicelength
-        assert start >= 0 # annotator hint
-        del items[start:]
+    start, stop, step, slicelength = w_slice.indices4(space, w_list.length())
+    w_list.deleteslice(start, step, slicelength)
 
 def setitem__List_ANY_ANY(space, w_list, w_index, w_any):
     idx = get_list_index(space, w_index)
     try:
-        w_list.wrappeditems[idx] = w_any
+        w_list.setitem(idx, w_any)
     except IndexError:
         raise OperationError(space.w_IndexError,
                              space.wrap("list index out of range"))
     return space.w_None
 
+def setitem__List_Slice_List(space, w_list, w_slice, w_other):
+    oldsize = w_list.length()
+    start, stop, step, slicelength = w_slice.indices4(space, oldsize)
+    w_list.setslice(start, step, slicelength, w_other)
+
 def setitem__List_Slice_ANY(space, w_list, w_slice, w_iterable):
-    oldsize = len(w_list.wrappeditems)
+    oldsize = w_list.length()
     start, stop, step, slicelength = w_slice.indices4(space, oldsize)
-
-    sequence2 = space.listview(w_iterable)
-    items = w_list.wrappeditems
-    _setitem_slice_helper(space, items, start, step, slicelength, sequence2,
-                          empty_elem=None)
-
-def _setitem_slice_helper(space, items, start, step, slicelength, sequence2,
-                          empty_elem):
-    assert slicelength >= 0
-    oldsize = len(items)
-    len2 = len(sequence2)
-    if step == 1:  # Support list resizing for non-extended slices
-        delta = slicelength - len2
-        if delta < 0:
-            delta = -delta
-            newsize = oldsize + delta
-            # XXX support this in rlist!
-            items += [empty_elem] * delta
-            lim = start+len2
-            i = newsize - 1
-            while i >= lim:
-                items[i] = items[i-delta]
-                i -= 1
-        elif start >= 0:
-            del items[start:start+delta]
-        else:
-            assert delta==0   # start<0 is only possible with slicelength==0
-    elif len2 != slicelength:  # No resize for extended slices
-        raise operationerrfmt(space.w_ValueError, "attempt to "
-              "assign sequence of size %d to extended slice of size %d",
-              len2, slicelength)
-
-    if sequence2 is items:
-        if step > 0:
-            # Always copy starting from the right to avoid
-            # having to make a shallow copy in the case where
-            # the source and destination lists are the same list.
-            i = len2 - 1
-            start += i*step
-            while i >= 0:
-                items[start] = sequence2[i]
-                start -= step
-                i -= 1
-            return
-        else:
-            # Make a shallow copy to more easily handle the reversal case
-            sequence2 = list(sequence2)
-    for i in range(len2):
-        items[start] = sequence2[i]
-        start += step
+    sequence_w = space.listview(w_iterable)
+    w_other = W_ListObject(space, sequence_w)
+    w_list.setslice(start, step, slicelength, w_other)
 
 app = gateway.applevel("""
     def listrepr(currently_in_repr, l):
@@ -352,7 +1176,7 @@
 listrepr = app.interphook("listrepr")
 
 def repr__List(space, w_list):
-    if len(w_list.wrappeditems) == 0:
+    if w_list.length() == 0:
         return space.wrap('[]')
     ec = space.getexecutioncontext()
     w_currently_in_repr = ec._py_repr
@@ -362,9 +1186,9 @@
 
 def list_insert__List_ANY_ANY(space, w_list, w_where, w_any):
     where = space.int_w(w_where)
-    length = len(w_list.wrappeditems)
+    length = w_list.length()
     index = get_positive_index(where, length)
-    w_list.wrappeditems.insert(index, w_any)
+    w_list.insert(index, w_any)
     return space.w_None
 
 def get_positive_index(where, length):
@@ -374,45 +1198,51 @@
             where = 0
     elif where > length:
         where = length
+    assert where >= 0
     return where
 
 def list_append__List_ANY(space, w_list, w_any):
-    w_list.wrappeditems.append(w_any)
+    w_list.append(w_any)
     return space.w_None
 
 def list_extend__List_List(space, w_list, w_other):
-    w_list.wrappeditems += w_other.wrappeditems
+    w_list.extend(w_other)
     return space.w_None
 
 def list_extend__List_ANY(space, w_list, w_any):
-    w_list.wrappeditems += space.listview(w_any)
+    w_other = W_ListObject(space, space.listview(w_any))
+    w_list.extend(w_other)
     return space.w_None
 
-# note that the default value will come back wrapped!!!
-def list_pop__List_ANY(space, w_list, w_idx=-1):
-    items = w_list.wrappeditems
-    if len(items)== 0:
+# default of w_idx is space.w_None (see listtype.py)
+def list_pop__List_ANY(space, w_list, w_idx):
+    length = w_list.length()
+    if length == 0:
         raise OperationError(space.w_IndexError,
                              space.wrap("pop from empty list"))
+    # clearly differentiate between list.pop() and list.pop(index)
+    if space.is_w(w_idx, space.w_None):
+        return w_list.pop_end() # cannot raise because list is not empty
     if space.isinstance_w(w_idx, space.w_float):
         raise OperationError(space.w_TypeError,
             space.wrap("integer argument expected, got float")
         )
     idx = space.int_w(space.int(w_idx))
+    if idx < 0:
+        idx += length
     try:
-        return items.pop(idx)
+        return w_list.pop(idx)
     except IndexError:
         raise OperationError(space.w_IndexError,
                              space.wrap("pop index out of range"))
 
 def list_remove__List_ANY(space, w_list, w_any):
     # needs to be safe against eq_w() mutating the w_list behind our back
-    items = w_list.wrappeditems
     i = 0
-    while i < len(items):
-        if space.eq_w(items[i], w_any):
-            if i < len(items): # if this is wrong the list was changed
-                del items[i]
+    while i < w_list.length():
+        if space.eq_w(w_list.getitem(i), w_any):
+            if i < w_list.length(): # if this is wrong the list was changed
+                w_list.pop(i)
             return space.w_None
         i += 1
     raise OperationError(space.w_ValueError,
@@ -420,12 +1250,11 @@
 
 def list_index__List_ANY_ANY_ANY(space, w_list, w_any, w_start, w_stop):
     # needs to be safe against eq_w() mutating the w_list behind our back
-    items = w_list.wrappeditems
-    size = len(items)
+    size = w_list.length()
     i, stop = slicetype.unwrap_start_stop(
             space, size, w_start, w_stop, True)
-    while i < stop and i < len(items):
-        if space.eq_w(items[i], w_any):
+    while i < stop and i < w_list.length():
+        if space.eq_w(w_list.getitem(i), w_any):
             return space.wrap(i)
         i += 1
     raise OperationError(space.w_ValueError,
@@ -435,15 +1264,14 @@
     # needs to be safe against eq_w() mutating the w_list behind our back
     count = 0
     i = 0
-    items = w_list.wrappeditems
-    while i < len(items):
-        if space.eq_w(items[i], w_any):
+    while i < w_list.length():
+        if space.eq_w(w_list.getitem(i), w_any):
             count += 1
         i += 1
     return space.wrap(count)
 
 def list_reverse__List(space, w_list):
-    w_list.wrappeditems.reverse()
+    w_list.reverse()
     return space.w_None
 
 # ____________________________________________________________
@@ -452,12 +1280,15 @@
 # Reverse a slice of a list in place, from lo up to (exclusive) hi.
 # (used in sort)
 
+TimSort = make_timsort_class()
+IntBaseTimSort = make_timsort_class()
+StringBaseTimSort = make_timsort_class()
+
 class KeyContainer(baseobjspace.W_Root):
     def __init__(self, w_key, w_item):
         self.w_key = w_key
         self.w_item = w_item
 
-TimSort = make_timsort_class()
 # NOTE: all the subclasses of TimSort should inherit from a common subclass,
 #       so make sure that only SimpleSort inherits directly from TimSort.
 #       This is necessary to hide the parent method TimSort.lt() from the
@@ -467,6 +1298,14 @@
         space = self.space
         return space.is_true(space.lt(a, b))
 
+class IntSort(IntBaseTimSort):
+    def lt(self, a, b):
+        return a < b
+
+class StringSort(StringBaseTimSort):
+    def lt(self, a, b):
+        return a < b
+
 class CustomCompareSort(SimpleSort):
     def lt(self, a, b):
         space = self.space
@@ -495,6 +1334,7 @@
         return CustomCompareSort.lt(self, a.w_key, b.w_key)
 
 def list_sort__List_ANY_ANY_ANY(space, w_list, w_cmp, w_keyfunc, w_reverse):
+
     has_cmp = not space.is_w(w_cmp, space.w_None)
     has_key = not space.is_w(w_keyfunc, space.w_None)
     has_reverse = space.is_true(w_reverse)
@@ -509,9 +1349,13 @@
         if has_key:
             sorterclass = CustomKeySort
         else:
-            sorterclass = SimpleSort
-    items = w_list.wrappeditems
-    sorter = sorterclass(items, len(items))
+            if w_list.strategy is space.fromcache(ObjectListStrategy):
+                sorterclass = SimpleSort
+            else:
+                w_list.sort(has_reverse)
+                return space.w_None
+
+    sorter = sorterclass(w_list.getitems(), w_list.length())
     sorter.space = space
     sorter.w_cmp = w_cmp
 
@@ -519,8 +1363,8 @@
         # The list is temporarily made empty, so that mutations performed
         # by comparison functions can't affect the slice of memory we're
         # sorting (allowing mutations during sorting is an IndexError or
-        # core-dump factory, since wrappeditems may change).
-        w_list.wrappeditems = []
+        # core-dump factory, since the storage may change).
+        w_list.__init__(space, [])
 
         # wrap each item in a KeyContainer if needed
         if has_key:
@@ -550,10 +1394,10 @@
                     sorter.list[i] = w_obj.w_item
 
         # check if the user mucked with the list during the sort
-        mucked = len(w_list.wrappeditems) > 0
+        mucked = w_list.length() > 0
 
         # put the items back into the list
-        w_list.wrappeditems = sorter.list
+        w_list.__init__(space, sorter.list)
 
     if mucked:
         raise OperationError(space.w_ValueError,
diff --git a/pypy/objspace/std/listtype.py b/pypy/objspace/std/listtype.py
--- a/pypy/objspace/std/listtype.py
+++ b/pypy/objspace/std/listtype.py
@@ -11,7 +11,7 @@
 list_extend   = SMM('extend', 2,
                     doc='L.extend(iterable) -- extend list by appending'
                         ' elements from the iterable')
-list_pop      = SMM('pop',    2, defaults=(-1,),
+list_pop      = SMM('pop',    2, defaults=(None,),
                     doc='L.pop([index]) -> item -- remove and return item at'
                         ' index (default last)')
 list_remove   = SMM('remove', 2,
@@ -43,7 +43,7 @@
 def descr__new__(space, w_listtype, __args__):
     from pypy.objspace.std.listobject import W_ListObject
     w_obj = space.allocate_instance(W_ListObject, w_listtype)
-    W_ListObject.__init__(w_obj, [])
+    W_ListObject.__init__(w_obj, space, [])
     return w_obj
 
 # ____________________________________________________________
diff --git a/pypy/objspace/std/marshal_impl.py b/pypy/objspace/std/marshal_impl.py
--- a/pypy/objspace/std/marshal_impl.py
+++ b/pypy/objspace/std/marshal_impl.py
@@ -300,7 +300,7 @@
 register(TYPE_TUPLE, unmarshal_Tuple)
 
 def marshal_w__List(space, w_list, m):
-    items = w_list.wrappeditems[:]
+    items = w_list.getitems()[:]
     m.put_tuple_w(TYPE_LIST, items)
 
 def unmarshal_List(space, u, tc):
diff --git a/pypy/objspace/std/model.py b/pypy/objspace/std/model.py
--- a/pypy/objspace/std/model.py
+++ b/pypy/objspace/std/model.py
@@ -25,8 +25,6 @@
                         "ropeobject.W_RopeIterObject"],
     "withropeunicode": ["ropeunicodeobject.W_RopeUnicodeObject",
                         "ropeunicodeobject.W_RopeUnicodeIterObject"],
-    "withrangelist"  : ["rangeobject.W_RangeListObject",
-                        "rangeobject.W_RangeIterObject"],
     "withtproxy" : ["proxyobject.W_TransparentList",
                     "proxyobject.W_TransparentDict"],
 }
@@ -253,12 +251,6 @@
                 (unicodeobject.W_UnicodeObject,
                                        strbufobject.delegate_buf2unicode)
                 ]
-        if config.objspace.std.withrangelist:
-            from pypy.objspace.std import rangeobject
-            self.typeorder[rangeobject.W_RangeListObject] += [
-                (listobject.W_ListObject,
-                                       rangeobject.delegate_range2list),
-                ]
         if config.objspace.std.withsmalltuple:
             from pypy.objspace.std import smalltupleobject
             self.typeorder[smalltupleobject.W_SmallTupleObject] += [
diff --git a/pypy/objspace/std/objspace.py b/pypy/objspace/std/objspace.py
--- a/pypy/objspace/std/objspace.py
+++ b/pypy/objspace/std/objspace.py
@@ -301,7 +301,10 @@
         return wraptuple(self, list_w)
 
     def newlist(self, list_w):
-        return W_ListObject(list_w)
+        return W_ListObject(self, list_w)
+
+    def newlist_str(self, list_s):
+        return W_ListObject.newlist_str(self, list_s)
 
     def newdict(self, module=False, instance=False, classofinstance=None,
                 strdict=False):
@@ -391,7 +394,7 @@
         if isinstance(w_obj, W_TupleObject):
             t = w_obj.wrappeditems[:]
         elif isinstance(w_obj, W_ListObject):
-            t = w_obj.wrappeditems[:]
+            t = w_obj.getitems_copy()
         else:
             return ObjSpace.unpackiterable(self, w_obj, expected_length)
         if expected_length != -1 and len(t) != expected_length:
@@ -405,7 +408,8 @@
         if isinstance(w_obj, W_TupleObject):
             t = w_obj.wrappeditems
         elif isinstance(w_obj, W_ListObject):
-            t = w_obj.wrappeditems[:]
+            # XXX this can copy twice
+            t = w_obj.getitems()[:]
         else:
             if unroll:
                 return make_sure_not_resized(ObjSpace.unpackiterable_unroll(
@@ -423,7 +427,7 @@
 
     def listview(self, w_obj, expected_length=-1):
         if isinstance(w_obj, W_ListObject):
-            t = w_obj.wrappeditems
+            t = w_obj.getitems()
         elif isinstance(w_obj, W_TupleObject):
             t = w_obj.wrappeditems[:]
         else:
@@ -432,6 +436,11 @@
             raise self._wrap_expected_length(expected_length, len(t))
         return t
 
+    def listview_str(self, w_obj):
+        if isinstance(w_obj, W_ListObject):
+            return w_obj.getitems_str()
+        return None
+
     def sliceindices(self, w_slice, w_length):
         if isinstance(w_slice, W_SliceObject):
             a, b, c = w_slice.indices3(self, self.int_w(w_length))
@@ -445,14 +454,76 @@
         return self.int_w(l_w[0]), self.int_w(l_w[1]), self.int_w(l_w[2])
 
     def is_(self, w_one, w_two):
-        if w_one is w_two:
-            return self.w_True
-        return self.w_False
+        return self.newbool(self.is_w(w_one, w_two))
 
-    # short-cut
     def is_w(self, w_one, w_two):
+        from pypy.rlib.longlong2float import float2longlong
+        w_typeone = self.type(w_one)
+        # cannot use self.is_w here to not get infinite recursion
+        if w_typeone is self.w_int:
+            return (self.type(w_two) is self.w_int and
+                    self.int_w(w_one) == self.int_w(w_two))
+        elif w_typeone is self.w_float:
+            if self.type(w_two) is not self.w_float:
+                return False
+            one = float2longlong(self.float_w(w_one))
+            two = float2longlong(self.float_w(w_two))
+            return one == two
+        elif w_typeone is self.w_long:
+            return (self.type(w_two) is self.w_long and
+                    self.bigint_w(w_one).eq(self.bigint_w(w_two)))
+        elif w_typeone is self.w_complex:
+            if self.type(w_two) is not self.w_complex:
+                return False
+            real1 = self.float_w(self.getattr(w_one, self.wrap("real")))
+            real2 = self.float_w(self.getattr(w_two, self.wrap("real")))
+            imag1 = self.float_w(self.getattr(w_one, self.wrap("imag")))
+            imag2 = self.float_w(self.getattr(w_two, self.wrap("imag")))
+            real1 = float2longlong(real1)
+            real2 = float2longlong(real2)
+            imag1 = float2longlong(imag1)
+            imag2 = float2longlong(imag2)
+            return real1 == real2 and imag1 == imag2
+        elif w_typeone is self.w_str:
+            return (self.type(w_two) is self.w_str and
+                    self.str_w(w_one) is self.str_w(w_two))
+        elif w_typeone is self.w_unicode:
+            return (self.type(w_two) is self.w_unicode and
+                    self.unicode_w(w_one) is self.unicode_w(w_two))
         return w_one is w_two
 
+    def id(self, w_obj):
+        from pypy.rlib.rbigint import rbigint
+        from pypy.rlib import objectmodel
+        from pypy.rlib.longlong2float import float2longlong
+        w_type = self.type(w_obj)
+        if w_type is self.w_int:
+            tag = 1
+            return self.or_(self.lshift(w_obj, self.wrap(3)), self.wrap(tag))
+        elif w_type is self.w_long:
+            tag = 3
+            return self.or_(self.lshift(w_obj, self.wrap(3)), self.wrap(tag))
+        elif w_type is self.w_float:
+            tag = 5
+            val = float2longlong(self.float_w(w_obj))
+            w_obj = self.newlong_from_rbigint(rbigint.fromrarith_int(val))
+            return self.or_(self.lshift(w_obj, self.wrap(3)), self.wrap(tag))
+        elif w_type is self.w_complex:
+            real = self.float_w(self.getattr(w_obj, self.wrap("real")))
+            imag = self.float_w(self.getattr(w_obj, self.wrap("imag")))
+            tag = 5
+            real_b = rbigint.fromrarith_int(float2longlong(real))
+            imag_b = rbigint.fromrarith_int(float2longlong(imag))
+            val = real_b.lshift(8 * 8).or_(imag_b).lshift(3).or_(rbigint.fromint(3))
+            return self.newlong_from_rbigint(val)
+        elif w_type is self.w_str:
+            res = objectmodel.compute_unique_id(self.str_w(w_obj))
+        elif w_type is self.w_unicode:
+            res = objectmodel.compute_unique_id(self.unicode_w(w_obj))
+        else:
+            res = objectmodel.compute_unique_id(w_obj)
+        return self.wrap(res)
+
     def is_true(self, w_obj):
         # a shortcut for performance
         # NOTE! this method is typically overridden by builtinshortcut.py.
diff --git a/pypy/objspace/std/rangeobject.py b/pypy/objspace/std/rangeobject.py
deleted file mode 100644
--- a/pypy/objspace/std/rangeobject.py
+++ /dev/null
@@ -1,237 +0,0 @@
-from pypy.interpreter.error import OperationError
-from pypy.objspace.std.model import registerimplementation, W_Object
-from pypy.objspace.std.register_all import register_all
-from pypy.objspace.std.multimethod import FailedToImplement
-from pypy.objspace.std.noneobject import W_NoneObject
-from pypy.objspace.std.inttype import wrapint
-from pypy.objspace.std.sliceobject import W_SliceObject, normalize_simple_slice
-from pypy.objspace.std.listobject import W_AbstractListObject, W_ListObject
-from pypy.objspace.std import listtype, iterobject, slicetype
-from pypy.interpreter import gateway, baseobjspace
-
-def length(start, stop, step):
-    if step > 0:
-        if stop <= start:
-            return 0
-        return (stop - start + step - 1)/step
-
-    else:  # step must be < 0
-        if stop >= start:
-            return 0
-        return (start - stop - step  - 1)/-step
-
-
-class W_RangeListObject(W_AbstractListObject):
-    typedef = listtype.list_typedef
-
-    def __init__(w_self, start, step, length):
-        assert step != 0
-        w_self.start = start
-        w_self.step = step
-        w_self.length = length
-        w_self.w_list = None
-
-    def force(w_self, space):
-        if w_self.w_list is not None:
-            return w_self.w_list
-        start = w_self.start
-        step = w_self.step
-        length = w_self.length
-        if not length:
-            w_self.w_list = space.newlist([])
-            return w_self.w_list
-
-        arr = [None] * length  # this is to avoid using append.
-
-        i = start
-        n = 0
-        while n < length:
-            arr[n] = wrapint(space, i)
-            i += step
-            n += 1
-
-        w_self.w_list = space.newlist(arr)
-        return w_self.w_list
-
-    def getitem(w_self, i):
-        if i < 0:
-            i += w_self.length
-            if i < 0:
-                raise IndexError
-        elif i >= w_self.length:
-            raise IndexError
-        return w_self.start + i * w_self.step
-
-    def getitem_unchecked(w_self, i):
-        # bounds not checked, on purpose
-        return w_self.start + i * w_self.step
-
-    def __repr__(w_self):
-        if w_self.w_list is None:
-            return "W_RangeListObject(%s, %s, %s)" % (
-                w_self.start, w_self.step, w_self.length)
-        else:
-            return "W_RangeListObject(%r)" % (w_self.w_list, )
-
-def delegate_range2list(space, w_rangelist):
-    return w_rangelist.force(space)
-
-def len__RangeList(space, w_rangelist):
-    if w_rangelist.w_list is not None:
-        return space.len(w_rangelist.w_list)
-    return wrapint(space, w_rangelist.length)
-
-
-def getitem__RangeList_ANY(space, w_rangelist, w_index):
-    if w_rangelist.w_list is not None:
-        return space.getitem(w_rangelist.w_list, w_index)
-    idx = space.getindex_w(w_index, space.w_IndexError, "list index")
-    try:
-        return wrapint(space, w_rangelist.getitem(idx))
-    except IndexError:
-        raise OperationError(space.w_IndexError,
-                             space.wrap("list index out of range"))
-
-def getitem__RangeList_Slice(space, w_rangelist, w_slice):
-    if w_rangelist.w_list is not None:
-        return space.getitem(w_rangelist.w_list, w_slice)
-    length = w_rangelist.length
-    start, stop, step, slicelength = w_slice.indices4(space, length)
-    assert slicelength >= 0
-    rangestart = w_rangelist.getitem_unchecked(start)
-    rangestep = w_rangelist.step * step
-    return W_RangeListObject(rangestart, rangestep, slicelength)
-
-def getslice__RangeList_ANY_ANY(space, w_rangelist, w_start, w_stop):
-    if w_rangelist.w_list is not None:
-        return space.getslice(w_rangelist.w_list, w_start, w_stop)
-    length = w_rangelist.length
-    start, stop = normalize_simple_slice(space, length, w_start, w_stop)
-    slicelength = stop - start
-    assert slicelength >= 0
-    rangestart = w_rangelist.getitem_unchecked(start)
-    rangestep = w_rangelist.step
-    return W_RangeListObject(rangestart, rangestep, slicelength)
-
-def iter__RangeList(space, w_rangelist):
-    return W_RangeIterObject(w_rangelist)
-
-def repr__RangeList(space, w_rangelist):
-    if w_rangelist.w_list is not None:
-        return space.repr(w_rangelist.w_list)
-    if w_rangelist.length == 0:
-        return space.wrap('[]')
-    result = [''] * w_rangelist.length
-    i = w_rangelist.start
-    n = 0
-    while n < w_rangelist.length:
-        result[n] = str(i)
-        i += w_rangelist.step
-        n += 1
-    return space.wrap("[" + ", ".join(result) + "]")
-
-def inplace_add__RangeList_ANY(space, w_rangelist, w_iterable2):
-    space.inplace_add(w_rangelist.force(space), w_iterable2)
-    return w_rangelist
-
-def inplace_mul__RangeList_ANY(space, w_rangelist, w_number):
-    space.inplace_mul(w_rangelist.force(space), w_number)
-    return w_rangelist
-
-
-def list_pop__RangeList_ANY(space, w_rangelist, w_idx=-1):
-    if w_rangelist.w_list is not None:
-        raise FailedToImplement
-    length = w_rangelist.length
-    if length == 0:
-        raise OperationError(space.w_IndexError,
-                             space.wrap("pop from empty list"))
-    if space.isinstance_w(w_idx, space.w_float):
-        raise OperationError(space.w_TypeError,
-            space.wrap("integer argument expected, got float")
-        )
-    idx = space.int_w(space.int(w_idx))
-    if idx == 0:
-        result = w_rangelist.start
-        w_rangelist.start += w_rangelist.step
-        w_rangelist.length -= 1
-        return wrapint(space, result)
-    if idx == -1 or idx == length - 1:
-        w_rangelist.length -= 1
-        return wrapint(
-            space, w_rangelist.start + (length - 1) * w_rangelist.step)
-    if idx >= w_rangelist.length:
-        raise OperationError(space.w_IndexError,
-                             space.wrap("pop index out of range"))
-    raise FailedToImplement
-
-def list_reverse__RangeList(space, w_rangelist):
-    # probably somewhat useless, but well...
-    if w_rangelist.w_list is not None:
-        raise FailedToImplement
-    w_rangelist.start = w_rangelist.getitem_unchecked(w_rangelist.length-1)
-    w_rangelist.step = -w_rangelist.step
-
-def list_sort__RangeList_None_None_ANY(space, w_rangelist, w_cmp,
-                                       w_keyfunc, w_reverse):
-    # even more useless but fun
-    has_reverse = space.is_true(w_reverse)
-    if w_rangelist.w_list is not None:
-        raise FailedToImplement
-    if has_reverse:
-        factor = -1
-    else:
-        factor = 1
-    reverse = w_rangelist.step * factor < 0
-    if reverse:
-        w_rangelist.start = w_rangelist.getitem_unchecked(w_rangelist.length-1)
-        w_rangelist.step = -w_rangelist.step
-    return space.w_None
-
-
-class W_RangeIterObject(iterobject.W_AbstractSeqIterObject):
-    pass
-
-def iter__RangeIter(space, w_rangeiter):
-    return w_rangeiter
-
-def next__RangeIter(space, w_rangeiter):
-    w_rangelist = w_rangeiter.w_seq
-    if w_rangelist is None:
-        raise OperationError(space.w_StopIteration, space.w_None)
-    assert isinstance(w_rangelist, W_RangeListObject)
-    index = w_rangeiter.index
-    if w_rangelist.w_list is not None:
-        try:
-            w_item = space.getitem(w_rangelist.w_list,
-                                   wrapint(space, index))
-        except OperationError, e:
-            w_rangeiter.w_seq = None
-            if not e.match(space, space.w_IndexError):
-                raise
-            raise OperationError(space.w_StopIteration, space.w_None)
-    else:
-        if index >= w_rangelist.length:
-            w_rangeiter.w_seq = None
-            raise OperationError(space.w_StopIteration, space.w_None)
-        w_item = wrapint(
-            space,
-            w_rangelist.getitem_unchecked(index))
-    w_rangeiter.index = index + 1
-    return w_item
-
-# XXX __length_hint__()
-##def len__RangeIter(space,  w_rangeiter):
-##    if w_rangeiter.w_seq is None:
-##        return wrapint(space, 0)
-##    index = w_rangeiter.index
-##    w_length = space.len(w_rangeiter.w_seq)
-##    w_len = space.sub(w_length, wrapint(space, index))
-##    if space.is_true(space.lt(w_len, wrapint(space, 0))):
-##        w_len = wrapint(space, 0)
-##    return w_len
-
-registerimplementation(W_RangeListObject)
-registerimplementation(W_RangeIterObject)
-
-register_all(vars(), listtype)
diff --git a/pypy/objspace/std/stringobject.py b/pypy/objspace/std/stringobject.py
--- a/pypy/objspace/std/stringobject.py
+++ b/pypy/objspace/std/stringobject.py
@@ -11,7 +11,7 @@
 from pypy.objspace.std.listobject import W_ListObject
 from pypy.objspace.std.noneobject import W_NoneObject
 from pypy.objspace.std.tupleobject import W_TupleObject
-from pypy.rlib.rstring import StringBuilder
+from pypy.rlib.rstring import StringBuilder, split
 from pypy.interpreter.buffer import StringBuffer
 
 from pypy.objspace.std.stringtype import sliced, wrapstr, wrapchar, \
@@ -220,7 +220,7 @@
 
 def str_split__String_None_ANY(space, w_self, w_none, w_maxsplit=-1):
     maxsplit = space.int_w(w_maxsplit)
-    res_w = []
+    res = []
     value = w_self._value
     length = len(value)
     i = 0
@@ -243,12 +243,12 @@
             maxsplit -= 1   # NB. if it's already < 0, it stays < 0
 
         # the word is value[i:j]
-        res_w.append(sliced(space, value, i, j, w_self))
+        res.append(value[i:j])
 
         # continue to look from the character following the space after the word
         i = j + 1
 
-    return space.newlist(res_w)
+    return space.newlist_str(res)
 
 def str_split__String_String_ANY(space, w_self, w_by, w_maxsplit=-1):
     maxsplit = space.int_w(w_maxsplit)
@@ -258,33 +258,26 @@
     if bylen == 0:
         raise OperationError(space.w_ValueError, space.wrap("empty separator"))
 
-    res_w = []
-    start = 0
     if bylen == 1 and maxsplit < 0:
+        res = []
+        start = 0
         # fast path: uses str.rfind(character) and str.count(character)
         by = by[0]    # annotator hack: string -> char
         count = value.count(by)
-        res_w = [None] * (count + 1)
+        res = [None] * (count + 1)
         end = len(value)
         while count >= 0:
             assert end >= 0
             prev = value.rfind(by, 0, end)
             start = prev + 1
             assert start >= 0
-            res_w[count] = sliced(space, value, start, end, w_self)
+            res[count] = value[start:end]
             count -= 1
             end = prev
     else:
-        while maxsplit != 0:
-            next = value.find(by, start)
-            if next < 0:
-                break
-            res_w.append(sliced(space, value, start, next, w_self))
-            start = next + bylen
-            maxsplit -= 1   # NB. if it's already < 0, it stays < 0
-        res_w.append(sliced(space, value, start, len(value), w_self))
+        res = split(value, by, maxsplit)
 
-    return space.newlist(res_w)
+    return space.newlist_str(res)
 
 def str_rsplit__String_None_ANY(space, w_self, w_none, w_maxsplit=-1):
     maxsplit = space.int_w(w_maxsplit)
@@ -352,6 +345,11 @@
                                                        sliced)
 
 def str_join__String_ANY(space, w_self, w_list):
+    l = space.listview_str(w_list)
+    if l is not None:
+        if len(l) == 1:
+            return space.wrap(l[0])
+        return space.wrap(w_self._value.join(l))
     list_w = space.listview(w_list)
     size = len(list_w)
 
diff --git a/pypy/objspace/std/test/test_dictmultiobject.py b/pypy/objspace/std/test/test_dictmultiobject.py
--- a/pypy/objspace/std/test/test_dictmultiobject.py
+++ b/pypy/objspace/std/test/test_dictmultiobject.py
@@ -577,15 +577,17 @@
         assert getattr(a, s) == 42
 
     def test_setattr_string_identify(self):
-        attrs = []
+        class StrHolder(object):
+            pass
+        holder = StrHolder()
         class A(object):
             def __setattr__(self, attr, value):
-                attrs.append(attr)
+                holder.seen = attr
 
         a = A()
         s = "abc"
         setattr(a, s, 123)
-        assert attrs[0] is s
+        assert holder.seen is s
 
 class AppTestDictViews:
     def test_dictview(self):
diff --git a/pypy/objspace/std/test/test_listobject.py b/pypy/objspace/std/test/test_listobject.py
--- a/pypy/objspace/std/test/test_listobject.py
+++ b/pypy/objspace/std/test/test_listobject.py
@@ -1,3 +1,4 @@
+# coding: iso-8859-15
 import random
 from pypy.objspace.std.listobject import W_ListObject
 from pypy.interpreter.error import OperationError
@@ -8,25 +9,25 @@
 class TestW_ListObject(object):
     def test_is_true(self):
         w = self.space.wrap
-        w_list = W_ListObject([])
+        w_list = W_ListObject(self.space, [])
         assert self.space.is_true(w_list) == False
-        w_list = W_ListObject([w(5)])
+        w_list = W_ListObject(self.space, [w(5)])
         assert self.space.is_true(w_list) == True
-        w_list = W_ListObject([w(5), w(3)])
+        w_list = W_ListObject(self.space, [w(5), w(3)])
         assert self.space.is_true(w_list) == True
 
     def test_len(self):
         w = self.space.wrap
-        w_list = W_ListObject([])
+        w_list = W_ListObject(self.space, [])
         assert self.space.eq_w(self.space.len(w_list), w(0))
-        w_list = W_ListObject([w(5)])
+        w_list = W_ListObject(self.space, [w(5)])
         assert self.space.eq_w(self.space.len(w_list), w(1))
-        w_list = W_ListObject([w(5), w(3), w(99)]*111)
+        w_list = W_ListObject(self.space, [w(5), w(3), w(99)]*111)
         assert self.space.eq_w(self.space.len(w_list), w(333))
- 
+
     def test_getitem(self):
         w = self.space.wrap
-        w_list = W_ListObject([w(5), w(3)])
+        w_list = W_ListObject(self.space, [w(5), w(3)])
         assert self.space.eq_w(self.space.getitem(w_list, w(0)), w(5))
         assert self.space.eq_w(self.space.getitem(w_list, w(1)), w(3))
         assert self.space.eq_w(self.space.getitem(w_list, w(-2)), w(5))
@@ -38,10 +39,19 @@
         self.space.raises_w(self.space.w_IndexError,
                             self.space.getitem, w_list, w(-3))
 
+    def test_getitems(self):
+        w = self.space.wrap
+        from pypy.objspace.std.listobject import make_range_list
+        r = make_range_list(self.space, 1,1,7)
+        l = [w(1),w(2),w(3),w(4),w(5),w(6),w(7)]
+        l2 = r.getitems()
+        for i in range(7):
+            assert self.space.eq_w(l[i], l2[i])
+
     def test_random_getitem(self):
         w = self.space.wrap
         s = list('qedx387tn3uixhvt 7fh387fymh3dh238 dwd-wq.dwq9')
-        w_list = W_ListObject(map(w, s))
+        w_list = W_ListObject(self.space, map(w, s))
         keys = range(-len(s)-5, len(s)+5)
         choices = keys + [None]*12
         stepchoices = [None, None, None, 1, 1, -1, -1, 2, -2,
@@ -64,7 +74,7 @@
 
     def test_iter(self):
         w = self.space.wrap
-        w_list = W_ListObject([w(5), w(3), w(99)])
+        w_list = W_ListObject(self.space, [w(5), w(3), w(99)])
         w_iter = self.space.iter(w_list)
         assert self.space.eq_w(self.space.next(w_iter), w(5))
         assert self.space.eq_w(self.space.next(w_iter), w(3))
@@ -74,7 +84,7 @@
 
     def test_contains(self):
         w = self.space.wrap
-        w_list = W_ListObject([w(5), w(3), w(99)])
+        w_list = W_ListObject(self.space, [w(5), w(3), w(99)])
         assert self.space.eq_w(self.space.contains(w_list, w(5)),
                            self.space.w_True)
         assert self.space.eq_w(self.space.contains(w_list, w(99)),
@@ -89,10 +99,10 @@
 
         def test1(testlist, start, stop, step, expected):
             w_slice  = self.space.newslice(w(start), w(stop), w(step))
-            w_list = W_ListObject([w(i) for i in testlist])
+            w_list = W_ListObject(self.space, [w(i) for i in testlist])
             w_result = self.space.getitem(w_list, w_slice)
             assert self.space.unwrap(w_result) == expected
-        
+
         for testlist in [[], [5,3,99]]:
             for start in [-2, 0, 1, 10]:
                 for end in [-1, 2, 999]:
@@ -110,11 +120,11 @@
 
         def test1(lhslist, start, stop, rhslist, expected):
             w_slice  = self.space.newslice(w(start), w(stop), w(1))
-            w_lhslist = W_ListObject([w(i) for i in lhslist])
-            w_rhslist = W_ListObject([w(i) for i in rhslist])
+            w_lhslist = W_ListObject(self.space, [w(i) for i in lhslist])
+            w_rhslist = W_ListObject(self.space, [w(i) for i in rhslist])
             self.space.setitem(w_lhslist, w_slice, w_rhslist)
             assert self.space.unwrap(w_lhslist) == expected
-        
+
 
         test1([5,7,1,4], 1, 3, [9,8],  [5,9,8,4])
         test1([5,7,1,4], 1, 3, [9],    [5,9,4])
@@ -125,14 +135,14 @@
 
     def test_add(self):
         w = self.space.wrap
-        w_list0 = W_ListObject([])
-        w_list1 = W_ListObject([w(5), w(3), w(99)])
-        w_list2 = W_ListObject([w(-7)] * 111)
+        w_list0 = W_ListObject(self.space, [])
+        w_list1 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list2 = W_ListObject(self.space, [w(-7)] * 111)
         assert self.space.eq_w(self.space.add(w_list1, w_list1),
-                           W_ListObject([w(5), w(3), w(99),
+                           W_ListObject(self.space, [w(5), w(3), w(99),
                                                w(5), w(3), w(99)]))
         assert self.space.eq_w(self.space.add(w_list1, w_list2),
-                           W_ListObject([w(5), w(3), w(99)] +
+                           W_ListObject(self.space, [w(5), w(3), w(99)] +
                                               [w(-7)] * 111))
         assert self.space.eq_w(self.space.add(w_list1, w_list0), w_list1)
         assert self.space.eq_w(self.space.add(w_list0, w_list2), w_list2)
@@ -142,8 +152,8 @@
         w = self.space.wrap
         arg = w(2)
         n = 3
-        w_lis = W_ListObject([arg])
-        w_lis3 = W_ListObject([arg]*n)
+        w_lis = W_ListObject(self.space, [arg])
+        w_lis3 = W_ListObject(self.space, [arg]*n)
         w_res = self.space.mul(w_lis, w(n))
         assert self.space.eq_w(w_lis3, w_res)
         # commute
@@ -152,9 +162,9 @@
 
     def test_setitem(self):
         w = self.space.wrap
-        w_list = W_ListObject([w(5), w(3)])
-        w_exp1 = W_ListObject([w(5), w(7)])
-        w_exp2 = W_ListObject([w(8), w(7)])
+        w_list = W_ListObject(self.space, [w(5), w(3)])
+        w_exp1 = W_ListObject(self.space, [w(5), w(7)])
+        w_exp2 = W_ListObject(self.space, [w(8), w(7)])
         self.space.setitem(w_list, w(1), w(7))
         assert self.space.eq_w(w_exp1, w_list)
         self.space.setitem(w_list, w(-2), w(8))
@@ -167,7 +177,7 @@
     def test_random_setitem_delitem(self):
         w = self.space.wrap
         s = range(39)
-        w_list = W_ListObject(map(w, s))
+        w_list = W_ListObject(self.space, map(w, s))
         expected = list(s)
         keys = range(-len(s)-5, len(s)+5)
         choices = keys + [None]*12
@@ -183,7 +193,7 @@
         for key in keys:
             if random.random() < 0.15:
                 random.shuffle(s)
-                w_list = W_ListObject(map(w, s))
+                w_list = W_ListObject(self.space, map(w, s))
                 expected = list(s)
             try:
                 value = expected[key]
@@ -218,11 +228,11 @@
 
     def test_eq(self):
         w = self.space.wrap
-        
-        w_list0 = W_ListObject([])
-        w_list1 = W_ListObject([w(5), w(3), w(99)])
-        w_list2 = W_ListObject([w(5), w(3), w(99)])
-        w_list3 = W_ListObject([w(5), w(3), w(99), w(-1)])
+
+        w_list0 = W_ListObject(self.space, [])
+        w_list1 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list2 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list3 = W_ListObject(self.space, [w(5), w(3), w(99), w(-1)])
 
         assert self.space.eq_w(self.space.eq(w_list0, w_list1),
                            self.space.w_False)
@@ -236,11 +246,11 @@
                            self.space.w_False)
     def test_ne(self):
         w = self.space.wrap
-        
-        w_list0 = W_ListObject([])
-        w_list1 = W_ListObject([w(5), w(3), w(99)])
-        w_list2 = W_ListObject([w(5), w(3), w(99)])
-        w_list3 = W_ListObject([w(5), w(3), w(99), w(-1)])
+
+        w_list0 = W_ListObject(self.space, [])
+        w_list1 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list2 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list3 = W_ListObject(self.space, [w(5), w(3), w(99), w(-1)])
 
         assert self.space.eq_w(self.space.ne(w_list0, w_list1),
                            self.space.w_True)
@@ -254,12 +264,12 @@
                            self.space.w_True)
     def test_lt(self):
         w = self.space.wrap
-        
-        w_list0 = W_ListObject([])
-        w_list1 = W_ListObject([w(5), w(3), w(99)])
-        w_list2 = W_ListObject([w(5), w(3), w(99)])
-        w_list3 = W_ListObject([w(5), w(3), w(99), w(-1)])
-        w_list4 = W_ListObject([w(5), w(3), w(9), w(-1)])
+
+        w_list0 = W_ListObject(self.space, [])
+        w_list1 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list2 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list3 = W_ListObject(self.space, [w(5), w(3), w(99), w(-1)])
+        w_list4 = W_ListObject(self.space, [w(5), w(3), w(9), w(-1)])
 
         assert self.space.eq_w(self.space.lt(w_list0, w_list1),
                            self.space.w_True)
@@ -273,15 +283,15 @@
                            self.space.w_True)
         assert self.space.eq_w(self.space.lt(w_list4, w_list3),
                            self.space.w_True)
-        
+
     def test_ge(self):
         w = self.space.wrap
-        
-        w_list0 = W_ListObject([])
-        w_list1 = W_ListObject([w(5), w(3), w(99)])
-        w_list2 = W_ListObject([w(5), w(3), w(99)])
-        w_list3 = W_ListObject([w(5), w(3), w(99), w(-1)])
-        w_list4 = W_ListObject([w(5), w(3), w(9), w(-1)])
+
+        w_list0 = W_ListObject(self.space, [])
+        w_list1 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list2 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list3 = W_ListObject(self.space, [w(5), w(3), w(99), w(-1)])
+        w_list4 = W_ListObject(self.space, [w(5), w(3), w(9), w(-1)])
 
         assert self.space.eq_w(self.space.ge(w_list0, w_list1),
                            self.space.w_False)
@@ -295,15 +305,15 @@
                            self.space.w_False)
         assert self.space.eq_w(self.space.ge(w_list4, w_list3),
                            self.space.w_False)
-        
+
     def test_gt(self):
         w = self.space.wrap
-        
-        w_list0 = W_ListObject([])
-        w_list1 = W_ListObject([w(5), w(3), w(99)])
-        w_list2 = W_ListObject([w(5), w(3), w(99)])
-        w_list3 = W_ListObject([w(5), w(3), w(99), w(-1)])
-        w_list4 = W_ListObject([w(5), w(3), w(9), w(-1)])
+
+        w_list0 = W_ListObject(self.space, [])
+        w_list1 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list2 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list3 = W_ListObject(self.space, [w(5), w(3), w(99), w(-1)])
+        w_list4 = W_ListObject(self.space, [w(5), w(3), w(9), w(-1)])
 
         assert self.space.eq_w(self.space.gt(w_list0, w_list1),
                            self.space.w_False)
@@ -317,15 +327,15 @@
                            self.space.w_False)
         assert self.space.eq_w(self.space.gt(w_list4, w_list3),
                            self.space.w_False)
-        
+
     def test_le(self):
         w = self.space.wrap
-        
-        w_list0 = W_ListObject([])
-        w_list1 = W_ListObject([w(5), w(3), w(99)])
-        w_list2 = W_ListObject([w(5), w(3), w(99)])
-        w_list3 = W_ListObject([w(5), w(3), w(99), w(-1)])
-        w_list4 = W_ListObject([w(5), w(3), w(9), w(-1)])
+
+        w_list0 = W_ListObject(self.space, [])
+        w_list1 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list2 = W_ListObject(self.space, [w(5), w(3), w(99)])
+        w_list3 = W_ListObject(self.space, [w(5), w(3), w(99), w(-1)])
+        w_list4 = W_ListObject(self.space, [w(5), w(3), w(9), w(-1)])
 
         assert self.space.eq_w(self.space.le(w_list0, w_list1),
                            self.space.w_True)
@@ -346,8 +356,62 @@
         import sys
         on_cpython = (option.runappdirect and
                             not hasattr(sys, 'pypy_translation_info'))
+        cls.w_on_cpython = cls.space.wrap(on_cpython)
 
-        cls.w_on_cpython = cls.space.wrap(on_cpython)
+    def test_getstrategyfromlist_w(self):
+        l0 = ["a", "2", "a", True]
+        # this raised TypeError on ListStrategies
+        l1 = ["a", "2", True, "a"]
+        l2 = [1, "2", "a", "a"]
+        assert sorted(l1) == sorted(l2)
+
+    def test_notequals(self):
+        assert [1,2,3,4] != [1,2,5,4]
+
+    def test_contains(self):
+        l = []
+        assert not l.__contains__(2)
+
+        l = [1,2,3]
+        assert l.__contains__(2)
+        assert not l.__contains__("2")
+        assert l.__contains__(1.0)
+
+        l = ["1","2","3"]
+        assert l.__contains__("2")
+        assert not l.__contains__(2)
+
+        l = range(4)
+        assert l.__contains__(2)
+        assert not l.__contains__("2")
+
+        l = [1,2,"3"]
+        assert l.__contains__(2)
+        assert not l.__contains__("2")
+
+        l = range(2, 20, 3) # = [2, 5, 8, 11, 14, 17]
+        assert l.__contains__(2)
+        assert l.__contains__(5)
+        assert l.__contains__(8)
+        assert l.__contains__(11)
+        assert l.__contains__(14)
+        assert l.__contains__(17)
+        assert not l.__contains__(3)
+        assert not l.__contains__(4)
+        assert not l.__contains__(7)
+        assert not l.__contains__(13)
+        assert not l.__contains__(20)
+
+        l = range(2, -20, -3) # [2, -1, -4, -7, -10, -13, -16, -19]
+        assert l.__contains__(2)
+        assert l.__contains__(-4)
+        assert l.__contains__(-13)
+        assert l.__contains__(-16)
+        assert l.__contains__(-19)
+        assert not l.__contains__(-17)
+        assert not l.__contains__(-3)
+        assert not l.__contains__(-20)
+        assert not l.__contains__(-21)
 
     def test_call_list(self):
         assert list('') == []
@@ -385,6 +449,13 @@
         l.extend([10])
         assert l == range(11)
 
+        l = []
+        m = [1,2,3]
+        l.extend(m)
+        m[0] = 5
+        assert m == [5,2,3]
+        assert l == [1,2,3]
+
     def test_extend_tuple(self):
         l = l0 = [1]
         l.extend((2,))
@@ -418,6 +489,10 @@
         assert l is l0
         assert l == [1]
 
+        l = ["c", "a", "d", "b"]
+        l.sort(reverse=True)
+        assert l == ["d", "c", "b", "a"]
+
     def test_sort_cmp(self):
         def lencmp(a,b): return cmp(len(a), len(b))
         l = [ 'a', 'fiver', 'tre', '' ]
@@ -459,6 +534,11 @@
         l.sort(reverse = True, key = lower)
         assert l == ['C', 'b', 'a']
 
+    def test_sort_simple_string(self):
+        l = ["a", "d", "c", "b"]
+        l.sort()
+        assert l == ["a", "b", "c", "d"]
+
     def test_getitem(self):
         l = [1, 2, 3, 4, 5, 6, 9]
         assert l[0] == 1
@@ -471,6 +551,21 @@
         assert l[-1] == 'c'
         assert l[-2] == 'b'
         raises(IndexError, "l[len(l)]")
+        l = []
+        raises(IndexError, "l[1]")
+
+    def test_setitem(self):
+
+        l = []
+        raises(IndexError, "l[1] = 2")
+
+        l = [5,3]
+        l[0] = 2
+        assert l == [2,3]
+
+        l = [5,3]
+        l[0] = "2"
+        assert l == ["2",3]
 
     def test_delitem(self):
         l = [1, 2, 3, 4, 5, 6, 9]
@@ -482,7 +577,7 @@
         assert l == [2, 3, 4, 6]
         raises(IndexError, "del l[len(l)]")
         raises(IndexError, "del l[-len(l)-1]")
-        
+
         l = l0 = ['a', 'b', 'c']
         del l[0]
         assert l == ['b', 'c']
@@ -513,7 +608,7 @@
         assert l[::] == l
         assert l[0::-2] == l
         assert l[-1::-5] == l
-        
+
         l = ['']
         assert l[1:] == []
         assert l[1::2] == []
@@ -523,6 +618,10 @@
         l.extend(['a', 'b'])
         assert l[::-1] == ['b', 'a', '']
 
+        l = [1,2,3,4,5]
+        assert l[1:0:None] == []
+        assert l[1:0] == []
+
     def test_delall(self):
         l = l0 = [1,2,3]
         del l[:]
@@ -564,6 +663,16 @@
         l1 += bar
         assert l1 == ('radd', bar, [1,2,3])
 
+    def test_add_lists(self):
+        l1 = [1,2,3]
+        l2 = [4,5,6]
+        l3 = l1 + l2
+        assert l3 == [1,2,3,4,5,6]
+
+        l4 = range(3)
+        l5 = l4 + l2
+        assert l5 == [0,1,2,4,5,6]
+
     def test_imul(self):
         l = l0 = [4,3]
         l *= 2
@@ -576,7 +685,7 @@
         l *= (-1)
         assert l is l0
         assert l == []
-        
+
         l = l0 = ['a', 'b']
         l *= 2
         assert l is l0
@@ -602,7 +711,7 @@
         c = range(10)
         assert c.index(0) == 0
         raises(ValueError, c.index, 10)
-        
+
         c = list('hello world')
         assert c.index('l') == 2
         raises(ValueError, c.index, '!')
@@ -650,7 +759,7 @@
         assert l == []
         assert l is l0
 
-    def test_ass_extended_slice(self):
+    def test_assign_extended_slice(self):
         l = l0 = ['a', 'b', 'c']
         l[::-1] = ['a', 'b', 'c']
         assert l == ['c', 'b', 'a']
@@ -662,6 +771,41 @@
         assert l == [0, 'b', 2]
         assert l is l0
 
+        l = [1,2,3]
+        raises(ValueError, "l[0:2:2] = [1,2,3,4]")
+        raises(ValueError, "l[::2] = []")
+
+        l = range(6)
+        l[::3] = ('a', 'b')
+        assert l == ['a', 1, 2, 'b', 4, 5]
+
+    def test_setslice_with_self(self):
+        l = [1,2,3,4]
+        l[:] = l
+        assert l == [1,2,3,4]
+
+        l = [1,2,3,4]
+        l[0:2] = l
+        assert l == [1,2,3,4,3,4]
+
+        l = [1,2,3,4]
+        l[0:2] = l
+        assert l == [1,2,3,4,3,4]
+
+        l = [1,2,3,4,5,6,7,8,9,10]
+        raises(ValueError, "l[5::-1] = l")
+
+        l = [1,2,3,4,5,6,7,8,9,10]
+        raises(ValueError, "l[::2] = l")
+
+        l = [1,2,3,4,5,6,7,8,9,10]
+        l[5:] = l
+        assert l == [1,2,3,4,5,1,2,3,4,5,6,7,8,9,10]
+
+        l = [1,2,3,4,5,6]
+        l[::-1] = l
+        assert l == [6,5,4,3,2,1]
+
     def test_recursive_repr(self):
         l = []
         assert repr(l) == '[]'
@@ -687,6 +831,10 @@
         l.append(4)
         assert l == range(5)
 
+        l = [1,2,3]
+        l.append("a")
+        assert l == [1,2,3,"a"]
+
     def test_count(self):
         c = list('hello')
         assert c.count('l') == 2
@@ -706,6 +854,14 @@
             ls.insert(0, i)
         assert len(ls) == 12
 
+        l = []
+        l.insert(4,2)
+        assert l == [2]
+
+        l = [1,2,3]
+        l.insert(0,"a")
+        assert l == ["a", 1, 2, 3]
+
     def test_pop(self):
         c = list('hello world')
         s = ''
@@ -719,6 +875,9 @@
         l.pop()
         assert l == range(9)
 
+        l = []
+        raises(IndexError, l.pop, 0)
+
     def test_pop_custom_int(self):
         class A(object):
             def __init__(self, x):
@@ -733,6 +892,22 @@
         assert l == range(9)
         raises(TypeError, range(10).pop, 1.0)
 
+    def test_pop_negative(self):
+        l1 = [1,2,3,4]
+        l2 = ["1", "2", "3", "4"]
+        l3 = range(5)
+        l4 = [1, 2, 3, "4"]
+
+        raises(IndexError, l1.pop, -5)
+        raises(IndexError, l2.pop, -5)
+        raises(IndexError, l3.pop, -6)
+        raises(IndexError, l4.pop, -5)
+
+        assert l1.pop(-2) == 3
+        assert l2.pop(-2) == "3"
+        assert l3.pop(-2) == 3
+        assert l4.pop(-2) == 3
+
     def test_remove(self):
         c = list('hello world')
         c.remove('l')
@@ -783,6 +958,20 @@
         l.remove(5)
         assert l[10:] == [0, 1, 2, 3, 4, 6, 7, 8, 9]
 
+    def test_mutate_while_contains(self):
+        class Mean(object):
+            def __init__(self, i):
+                self.i = i
+            def __eq__(self, other):
+                if self.i == 9 == other:
+                    del l[0]
+                    return True
+                else:
+                    return False
+        l = [Mean(i) for i in range(10)]
+        assert l.__contains__(9)
+        assert not l.__contains__(2)
+
     def test_mutate_while_extend(self):
         # this used to segfault pypy-c (with py.test -A)
         import sys
@@ -805,16 +994,36 @@
         res = l.__getslice__(0, 2)
         assert res == [1, 2]
 
+        l = []
+        assert l.__getslice__(0,2) == []
+
     def test___setslice__(self):
         l = [1,2,3,4]
         l.__setslice__(0, 2, [5, 6])
         assert l == [5, 6, 3, 4]
 
+        l = []
+        l.__setslice__(0,0,[3,4,5])
+        assert l == [3,4,5]
+
     def test___delslice__(self):
         l = [1,2,3,4]
         l.__delslice__(0, 2)
         assert l == [3, 4]
 
+    def test_unicode(self):
+        s = u"\ufffd\ufffd\ufffd"
+        assert s.encode("ascii", "replace") == "???"
+        assert s.encode("ascii", "ignore") == ""
+        l1 = [s.encode("ascii", "replace")]
+        assert l1[0] == "???"
+
+        l2 = [s.encode("ascii", "ignore")]
+        assert l2[0] == ""
+
+        l3 = [s]
+        assert l1[0].encode("ascii", "replace") == "???"
+
     def test_list_from_set(self):
         l = ['a']
         l.__init__(set('b'))
@@ -829,6 +1038,96 @@
         assert l == []
         assert list(g) == []
 
+class AppTestForRangeLists(AppTestW_ListObject):
+
+    def setup_class(cls):
+        cls.space = gettestobjspace(**{"objspace.std.withrangelist" :
+                                       True})
+
+    def test_range_simple_backwards(self):
+        x = range(5,1)
+        assert x == []
+
+    def test_range_big_start(self):
+        x = range(1,10)
+        x[22:0:-1] == range(1,10)
+
+    def test_range_list_invalid_slice(self):
+        x = [1,2,3,4]
+        assert x[10:0] == []
+        assert x[10:0:None] == []
+
+        x = range(1,5)
+        assert x[10:0] == []
+        assert x[10:0:None] == []
+
+        assert x[0:22] == [1,2,3,4]
+        assert x[-1:10] == [4]
+
+        assert x[0:22:None] == [1,2,3,4]
+        assert x[-1:10:None] == [4]
+
+    def test_range_backwards(self):
+        x = range(1,10)
+        assert x[22:-10] == []
+        assert x[22:-10:-1] == [9,8,7,6,5,4,3,2,1]
+        assert x[10:3:-1] == [9,8,7,6,5]
+        assert x[10:3:-2] == [9,7,5]
+        assert x[1:5:-1] == []
+
+    def test_sort_range(self):
+        l = range(3,10,3)
+        l.sort()
+        assert l == [3, 6, 9]
+        l.sort(reverse = True)
+        assert l == [9, 6, 3]
+        l.sort(reverse = True)
+        assert l == [9, 6, 3]
+        l.sort()
+        assert l == [3, 6, 9]
+
+    def test_slice(self):
+        l = []
+        l2 = range(3)
+        l.__setslice__(0,3,l2)
+        assert l == [0,1,2]
+
+    def test_getitem(self):
+        l = range(5)
+        raises(IndexError, "l[-10]")
+
+    def test_append(self):
+        l = range(5)
+        l.append(26)
+        assert l == [0,1,2,3,4,26]
+
+        l = range(5)
+        l.append("a")
+        assert l == [0,1,2,3,4,"a"]
+
+        l = range(5)
+        l.append(5)
+        assert l == [0,1,2,3,4,5]
+
+    def test_pop(self):
+        l = range(3)
+        assert l.pop(0) == 0
+
+    def test_setitem(self):
+        l = range(3)
+        l[0] = 1
+        assert l == [1,1,2]
+
+    def test_inset(self):
+        l = range(3)
+        l.insert(1,5)
+        assert l == [0,5,1,2]
+
+    def test_reverse(self):
+        l = range(3)
+        l.reverse()
+        assert l == [2,1,0]
+
 
 class AppTestListFastSubscr:
 
diff --git a/pypy/objspace/std/test/test_liststrategies.py b/pypy/objspace/std/test/test_liststrategies.py
new file mode 100644
--- /dev/null
+++ b/pypy/objspace/std/test/test_liststrategies.py
@@ -0,0 +1,419 @@
+from pypy.objspace.std.listobject import W_ListObject, EmptyListStrategy, ObjectListStrategy, IntegerListStrategy, StringListStrategy, RangeListStrategy, make_range_list
+from pypy.objspace.std import listobject
+from pypy.objspace.std.test.test_listobject import TestW_ListObject
+
+from pypy.conftest import gettestobjspace
+
+class TestW_ListStrategies(TestW_ListObject):
+
+    def test_check_strategy(self):
+        assert isinstance(W_ListObject(self.space, []).strategy, EmptyListStrategy)
+        assert isinstance(W_ListObject(self.space, [self.space.wrap(1),self.space.wrap('a')]).strategy, ObjectListStrategy)
+        assert isinstance(W_ListObject(self.space, [self.space.wrap(1),self.space.wrap(2),self.space.wrap(3)]).strategy, IntegerListStrategy)
+        assert isinstance(W_ListObject(self.space, [self.space.wrap('a'), self.space.wrap('b')]).strategy, StringListStrategy)
+
+    def test_empty_to_any(self):
+        l = W_ListObject(self.space, [])
+        assert isinstance(l.strategy, EmptyListStrategy)
+        l.append(self.space.wrap(1.))
+        assert isinstance(l.strategy, ObjectListStrategy)
+
+        l = W_ListObject(self.space, [])
+        assert isinstance(l.strategy, EmptyListStrategy)
+        l.append(self.space.wrap(1))
+        assert isinstance(l.strategy, IntegerListStrategy)
+
+        l = W_ListObject(self.space, [])
+        assert isinstance(l.strategy, EmptyListStrategy)
+        l.append(self.space.wrap('a'))
+        assert isinstance(l.strategy, StringListStrategy)
+
+    def test_int_to_any(self):
+        l = W_ListObject(self.space, [self.space.wrap(1),self.space.wrap(2),self.space.wrap(3)])
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.append(self.space.wrap(4))
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.append(self.space.wrap('a'))
+        assert isinstance(l.strategy, ObjectListStrategy)
+
+    def test_string_to_any(self):
+        l = W_ListObject(self.space, [self.space.wrap('a'),self.space.wrap('b'),self.space.wrap('c')])
+        assert isinstance(l.strategy, StringListStrategy)
+        l.append(self.space.wrap('d'))
+        assert isinstance(l.strategy, StringListStrategy)
+        l.append(self.space.wrap(3))
+        assert isinstance(l.strategy, ObjectListStrategy)
+
+    def test_setitem(self):
+        # This should work if test_listobject.py passes
+        l = W_ListObject(self.space, [self.space.wrap('a'),self.space.wrap('b'),self.space.wrap('c')])
+        assert self.space.eq_w(l.getitem(0), self.space.wrap('a'))
+        l.setitem(0, self.space.wrap('d'))
+        assert self.space.eq_w(l.getitem(0), self.space.wrap('d'))
+
+        assert isinstance(l.strategy, StringListStrategy)
+
+        # IntStrategy to ObjectStrategy
+        l = W_ListObject(self.space, [self.space.wrap(1),self.space.wrap(2),self.space.wrap(3)])
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.setitem(0, self.space.wrap('d'))
+        assert isinstance(l.strategy, ObjectListStrategy)
+
+        # StringStrategy to ObjectStrategy
+        l = W_ListObject(self.space, [self.space.wrap('a'),self.space.wrap('b'),self.space.wrap('c')])
+        assert isinstance(l.strategy, StringListStrategy)
+        l.setitem(0, self.space.wrap(2))
+        assert isinstance(l.strategy, ObjectListStrategy)
+
+    def test_insert(self):
+        # no change
+        l = W_ListObject(self.space, [self.space.wrap(1),self.space.wrap(2),self.space.wrap(3)])
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.insert(3, self.space.wrap(4))
+        assert isinstance(l.strategy, IntegerListStrategy)
+
+        # StringStrategy
+        l = W_ListObject(self.space, [self.space.wrap('a'),self.space.wrap('b'),self.space.wrap('c')])
+        assert isinstance(l.strategy, StringListStrategy)
+        l.insert(3, self.space.wrap(2))
+        assert isinstance(l.strategy, ObjectListStrategy)
+
+        # IntegerStrategy
+        l = W_ListObject(self.space, [self.space.wrap(1),self.space.wrap(2),self.space.wrap(3)])
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.insert(3, self.space.wrap('d'))
+        assert isinstance(l.strategy, ObjectListStrategy)
+
+        # EmptyStrategy
+        l = W_ListObject(self.space, [])
+        assert isinstance(l.strategy, EmptyListStrategy)
+        l.insert(0, self.space.wrap('a'))
+        assert isinstance(l.strategy, StringListStrategy)
+
+        l = W_ListObject(self.space, [])
+        assert isinstance(l.strategy, EmptyListStrategy)
+        l.insert(0, self.space.wrap(2))
+        assert isinstance(l.strategy, IntegerListStrategy)
+
+    def notest_list_empty_after_delete(self):
+        l = W_ListObject(self.space, [self.space.wrap(3)])
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.deleteitem(0)
+        assert isinstance(l.strategy, EmptyListStrategy)
+
+        l = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2)])
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.deleteslice(0, 1, 2)
+        assert isinstance(l.strategy, EmptyListStrategy)
+
+        l = W_ListObject(self.space, [self.space.wrap(1)])
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.pop(-1)
+        assert isinstance(l.strategy, EmptyListStrategy)
+
+    def test_setslice(self):
+        l = W_ListObject(self.space, [])
+        assert isinstance(l.strategy, EmptyListStrategy)
+        l.setslice(0, 1, 2, W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)]))
+        assert isinstance(l.strategy, IntegerListStrategy)
+
+        l = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.setslice(0, 1, 2, W_ListObject(self.space, [self.space.wrap(4), self.space.wrap(5), self.space.wrap(6)]))
+        assert isinstance(l.strategy, IntegerListStrategy)
+
+        l = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap('b'), self.space.wrap(3)])
+        assert isinstance(l.strategy, ObjectListStrategy)
+        l.setslice(0, 1, 2, W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)]))
+        assert isinstance(l.strategy, ObjectListStrategy)
+
+        l = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.setslice(0, 1, 2, W_ListObject(self.space, [self.space.wrap('a'), self.space.wrap('b'), self.space.wrap('c')]))
+        assert isinstance(l.strategy, ObjectListStrategy)
+
+    def test_setslice_List(self):
+
+        def wrapitems(items):
+            items_w = []
+            for i in items:
+                items_w.append(self.space.wrap(i))
+            return items_w
+
+        def keep_other_strategy(w_list, start, step, length, w_other):
+            other_strategy = w_other.strategy
+            w_list.setslice(start, step, length, w_other)
+            assert w_other.strategy is other_strategy
+
+        l = W_ListObject(self.space, wrapitems([1,2,3,4,5]))
+        other = W_ListObject(self.space, wrapitems(["a", "b", "c"]))
+        keep_other_strategy(l, 0, 2, other.length(), other)
+        assert l.strategy is self.space.fromcache(ObjectListStrategy)
+
+        l = W_ListObject(self.space, wrapitems([1,2,3,4,5]))
+        other = W_ListObject(self.space, wrapitems([6, 6, 6]))
+        keep_other_strategy(l, 0, 2, other.length(), other)
+        assert l.strategy is self.space.fromcache(IntegerListStrategy)
+
+        l = W_ListObject(self.space, wrapitems(["a","b","c","d","e"]))
+        other = W_ListObject(self.space, wrapitems(["a", "b", "c"]))
+        keep_other_strategy(l, 0, 2, other.length(), other)
+        assert l.strategy is self.space.fromcache(StringListStrategy)
+
+        l = W_ListObject(self.space, wrapitems(["a",3,"c",4,"e"]))
+        other = W_ListObject(self.space, wrapitems(["a", "b", "c"]))
+        keep_other_strategy(l, 0, 2, other.length(), other)
+        assert l.strategy is self.space.fromcache(ObjectListStrategy)
+
+        l = W_ListObject(self.space, wrapitems(["a",3,"c",4,"e"]))
+        other = W_ListObject(self.space, [])
+        keep_other_strategy(l, 0, 1, l.length(), other)
+        assert l.strategy is self.space.fromcache(ObjectListStrategy)
+
+    def test_empty_setslice_with_objectlist(self):
+        l = W_ListObject(self.space, [])
+        o = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap("2"), self.space.wrap(3)])
+        l.setslice(0, 1, o.length(), o)
+        assert l.getitems() == o.getitems()
+        l.append(self.space.wrap(17))
+        assert l.getitems() != o.getitems()
+
+    def test_extend(self):
+        l = W_ListObject(self.space, [])
+        assert isinstance(l.strategy, EmptyListStrategy)
+        l.extend(W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)]))
+        assert isinstance(l.strategy, IntegerListStrategy)
+
+        l = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.extend(W_ListObject(self.space, [self.space.wrap('a'), self.space.wrap('b'), self.space.wrap('c')]))
+        assert isinstance(l.strategy, ObjectListStrategy)
+
+        l = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.extend(W_ListObject(self.space, [self.space.wrap(4), self.space.wrap(5), self.space.wrap(6)]))
+        assert isinstance(l.strategy, IntegerListStrategy)
+
+    def test_empty_extend_with_any(self):
+        empty = W_ListObject(self.space, [])
+        assert isinstance(empty.strategy, EmptyListStrategy)
+        empty.extend(W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)]))
+        assert isinstance(empty.strategy, IntegerListStrategy)
+
+        empty = W_ListObject(self.space, [])
+        assert isinstance(empty.strategy, EmptyListStrategy)
+        empty.extend(W_ListObject(self.space, [self.space.wrap("a"), self.space.wrap("b"), self.space.wrap("c")]))
+        assert isinstance(empty.strategy, StringListStrategy)
+
+        empty = W_ListObject(self.space, [])
+        assert isinstance(empty.strategy, EmptyListStrategy)
+        r = make_range_list(self.space, 1,3,7)
+        empty.extend(r)
+        assert isinstance(empty.strategy, RangeListStrategy)
+        print empty.getitem(6)
+        assert self.space.is_true(self.space.eq(empty.getitem(1), self.space.wrap(4)))
+
+        empty = W_ListObject(self.space, [])
+        assert isinstance(empty.strategy, EmptyListStrategy)
+        empty.extend(W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)]))
+        assert isinstance(empty.strategy, IntegerListStrategy)
+
+        empty = W_ListObject(self.space, [])
+        assert isinstance(empty.strategy, EmptyListStrategy)
+        empty.extend(W_ListObject(self.space, []))
+        assert isinstance(empty.strategy, EmptyListStrategy)
+
+    def test_extend_other_with_empty(self):
+        l = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        assert isinstance(l.strategy, IntegerListStrategy)
+        l.extend(W_ListObject(self.space, []))
+        assert isinstance(l.strategy, IntegerListStrategy)
+
+    def test_rangelist(self):
+        l = make_range_list(self.space, 1,3,7)
+        assert isinstance(l.strategy, RangeListStrategy)
+        v = l.pop(5)
+        assert self.space.eq_w(v, self.space.wrap(16))
+        assert isinstance(l.strategy, IntegerListStrategy)
+
+        l = make_range_list(self.space, 1,3,7)
+        assert isinstance(l.strategy, RangeListStrategy)
+        v = l.pop(0)
+        assert self.space.eq_w(v, self.space.wrap(1))
+        assert isinstance(l.strategy, RangeListStrategy)
+        v = l.pop(l.length() - 1)
+        assert self.space.eq_w(v, self.space.wrap(19))
+        assert isinstance(l.strategy, RangeListStrategy)
+        v = l.pop_end()
+        assert self.space.eq_w(v, self.space.wrap(16))
+        assert isinstance(l.strategy, RangeListStrategy)
+
+        l = make_range_list(self.space, 1,3,7)
+        assert isinstance(l.strategy, RangeListStrategy)
+        l.append(self.space.wrap("string"))
+        assert isinstance(l.strategy, ObjectListStrategy)
+
+        l = make_range_list(self.space, 1,1,5)
+        assert isinstance(l.strategy, RangeListStrategy)
+        l.append(self.space.wrap(19))
+        assert isinstance(l.strategy, IntegerListStrategy)
+
+    def test_keep_range(self):
+        # simple list
+        l = make_range_list(self.space, 1,1,5)
+        assert isinstance(l.strategy, RangeListStrategy)
+        x = l.pop(0)
+        assert self.space.eq_w(x, self.space.wrap(1))
+        assert isinstance(l.strategy, RangeListStrategy)
+        l.pop(l.length()-1)
+        assert isinstance(l.strategy, RangeListStrategy)
+        l.append(self.space.wrap(5))
+        assert isinstance(l.strategy, RangeListStrategy)
+
+        # complex list
+        l = make_range_list(self.space, 1,3,5)
+        assert isinstance(l.strategy, RangeListStrategy)
+        l.append(self.space.wrap(16))
+        assert isinstance(l.strategy, RangeListStrategy)
+
+    def test_empty_range(self):
+        l = make_range_list(self.space, 0, 0, 0)
+        assert isinstance(l.strategy, EmptyListStrategy)
+
+        l = make_range_list(self.space, 1, 1, 10)
+        for i in l.getitems():
+            assert isinstance(l.strategy, RangeListStrategy)
+            l.pop(l.length()-1)
+
+        assert isinstance(l.strategy, RangeListStrategy)
+
+    def test_range_setslice(self):
+        l = make_range_list(self.space, 1, 3, 5)
+        assert isinstance(l.strategy, RangeListStrategy)
+        l.setslice(0, 1, 3, W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)]))
+        assert isinstance(l.strategy, IntegerListStrategy)
+
+    def test_get_items_copy(self):
+        l1 = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        l2 = l1.getitems()
+        l2.append(self.space.wrap(4))
+        assert not l2 == l1.getitems()
+
+        l1 = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap("two"), self.space.wrap(3)])
+        l2 = l1.getitems()
+        l2.append(self.space.wrap("four"))
+        assert l2 == l1.getitems()
+
+    def test_clone(self):
+        l1 = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        clone = l1.clone()
+        assert isinstance(clone.strategy, IntegerListStrategy)
+        clone.append(self.space.wrap(7))
+        assert not self.space.eq_w(l1, clone)
+
+    def test_add_does_not_use_getitems(self):
+        l1 = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        l1.getitems = None
+        l2 = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        l2.getitems = None
+        l3 = self.space.add(l1, l2)
+        l4 = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3), self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        assert self.space.eq_w(l3, l4)
+
+    def test_mul(self):
+        l1 = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        l2 = l1.mul(2)
+        l3 = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3), self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        assert self.space.eq_w(l2, l3)
+
+        l4 = make_range_list(self.space, 1, 1, 3)
+        assert self.space.eq_w(l4, l1)
+
+        l5 = l4.mul(2)
+        assert self.space.eq_w(l5, l3)
+
+    def test_mul_same_strategy_but_different_object(self):
+        l1 = W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3)])
+        l2 = l1.mul(1)
+        assert self.space.eq_w(l1, l2)
+        l1.setitem(0, self.space.wrap(5))
+        assert not self.space.eq_w(l1, l2)
+
+    def test_weird_rangelist_bug(self):
+        l = make_range_list(self.space, 1, 1, 3)
+        from pypy.objspace.std.listobject import getslice__List_ANY_ANY
+        # should not raise
+        assert getslice__List_ANY_ANY(self.space, l, self.space.wrap(15), self.space.wrap(2222)).strategy == self.space.fromcache(EmptyListStrategy)
+
+
+    def test_add_to_rangelist(self):
+        l1 = make_range_list(self.space, 1, 1, 3)
+        l2 = W_ListObject(self.space, [self.space.wrap(4), self.space.wrap(5)])
+        from pypy.objspace.std.listobject import add__List_List
+        l3 = add__List_List(self.space, l1, l2)
+        assert self.space.eq_w(l3, W_ListObject(self.space, [self.space.wrap(1), self.space.wrap(2), self.space.wrap(3), self.space.wrap(4), self.space.wrap(5)]))
+
+    def test_unicode(self):
+        l1 = W_ListObject(self.space, [self.space.wrap("eins"), self.space.wrap("zwei")])
+        assert isinstance(l1.strategy, StringListStrategy)
+        l2 = W_ListObject(self.space, [self.space.wrap(u"eins"), self.space.wrap(u"zwei")])
+        assert isinstance(l2.strategy, ObjectListStrategy)
+        l3 = W_ListObject(self.space, [self.space.wrap("eins"), self.space.wrap(u"zwei")])
+        assert isinstance(l3.strategy, ObjectListStrategy)
+
+    def test_listview_str(self):
+        space = self.space
+        assert space.listview_str(space.wrap("a")) is None
+        w_l = self.space.newlist([self.space.wrap('a'), self.space.wrap('b')])
+        assert space.listview_str(w_l) == ["a", "b"]
+
+    def test_string_join_uses_listview_str(self):
+        space = self.space
+        w_l = self.space.newlist([self.space.wrap('a'), self.space.wrap('b')])
+        w_l.getitems = None
+        assert space.str_w(space.call_method(space.wrap("c"), "join", w_l)) == "acb"
+
+    def test_string_join_returns_same_instance(self):
+        space = self.space
+        w_text = space.wrap("text")
+        w_l = self.space.newlist([w_text])
+        w_l.getitems = None
+        assert space.is_w(space.call_method(space.wrap(" -- "), "join", w_l), w_text)
+
+    def test_newlist_str(self):
+        space = self.space
+        l = ['a', 'b']
+        w_l = self.space.newlist_str(l)
+        assert isinstance(w_l.strategy, StringListStrategy)
+        assert space.listview_str(w_l) is l
+
+    def test_string_uses_newlist_str(self):
+        space = self.space
+        w_s = space.wrap("a b c")
+        space.newlist = None
+        try:
+            w_l = space.call_method(w_s, "split")
+            w_l2 = space.call_method(w_s, "split", space.wrap(" "))
+        finally:
+            del space.newlist
+        assert space.listview_str(w_l) == ["a", "b", "c"]
+        assert space.listview_str(w_l2) == ["a", "b", "c"]
+
+    def test_pop_without_argument_is_fast(self):
+        space = self.space
+        w_l = W_ListObject(space, [space.wrap(1), space.wrap(2), space.wrap(3)])
+        w_l.pop = None
+        w_res = listobject.list_pop__List_ANY(space, w_l, space.w_None) # does not crash
+        assert space.unwrap(w_res) == 3
+
+
+class TestW_ListStrategiesDisabled:
+    def setup_class(cls):
+        cls.space = gettestobjspace(**{"objspace.std.withliststrategies" :
+                                       False})
+
+    def test_check_strategy(self):
+        assert isinstance(W_ListObject(self.space, []).strategy, ObjectListStrategy)
+        assert isinstance(W_ListObject(self.space, [self.space.wrap(1),self.space.wrap('a')]).strategy, ObjectListStrategy)
+        assert isinstance(W_ListObject(self.space, [self.space.wrap(1),self.space.wrap(2),self.space.wrap(3)]).strategy, ObjectListStrategy)
+        assert isinstance(W_ListObject(self.space, [self.space.wrap('a'), self.space.wrap('b')]).strategy, ObjectListStrategy)
diff --git a/pypy/objspace/std/test/test_obj.py b/pypy/objspace/std/test/test_obj.py
--- a/pypy/objspace/std/test/test_obj.py
+++ b/pypy/objspace/std/test/test_obj.py
@@ -4,12 +4,24 @@
 class AppTestObject:
 
     def setup_class(cls):
+        from pypy.interpreter import gateway
         import sys
+
         cpython_behavior = (not option.runappdirect
                             or not hasattr(sys, 'pypy_translation_info'))
 
-        cls.w_cpython_behavior = cls.space.wrap(cpython_behavior)
-        cls.w_cpython_version = cls.space.wrap(tuple(sys.version_info))
+        space = cls.space
+        cls.w_cpython_behavior = space.wrap(cpython_behavior)
+        cls.w_cpython_version = space.wrap(tuple(sys.version_info))
+        cls.w_appdirect = space.wrap(option.runappdirect)
+        cls.w_cpython_apptest = space.wrap(option.runappdirect and not hasattr(sys, 'pypy_translation_info'))
+
+        def w_unwrap_wrap_unicode(space, w_obj):
+            return space.wrap(space.unicode_w(w_obj))
+        cls.w_unwrap_wrap_unicode = space.wrap(gateway.interp2app(w_unwrap_wrap_unicode))
+        def w_unwrap_wrap_str(space, w_obj):
+            return space.wrap(space.str_w(w_obj))
+        cls.w_unwrap_wrap_str = space.wrap(gateway.interp2app(w_unwrap_wrap_str))
 
     def test_hash_builtin(self):
         if not self.cpython_behavior:
@@ -103,10 +115,120 @@
                 return 123456
         assert A().__str__() == 123456
 
+
+    def test_is_on_primitives(self):
+        if self.cpython_apptest:
+            skip("cpython behaves differently")
+        assert 1 is 1
+        x = 1000000
+        assert x + 1 is int(str(x + 1))
+        assert 1 is not 1.0
+        assert 1 is not 1l
+        assert 1l is not 1.0
+        assert 1.1 is 1.1
+        assert 0.0 is not -0.0
+        for x in range(10):
+            assert x + 0.1 is x + 0.1
+        for x in range(10):
+            assert x + 1L is x + 1L
+        for x in range(10):
+            assert x+1j is x+1j
+            assert 1+x*1j is 1+x*1j
+        l = [1]
+        assert l[0] is l[0]
+
+    def test_is_on_strs(self):
+        if self.appdirect:
+            skip("cannot run this test as apptest")
+        l = ["a"]
+        assert l[0] is l[0]
+        u = u"a"
+        assert self.unwrap_wrap_unicode(u) is u
+        s = "a"
+        assert self.unwrap_wrap_str(s) is s
+
+    def test_id_on_primitives(self):
+        if self.cpython_apptest:
+            skip("cpython behaves differently")
+        assert id(1) == (1 << 3) + 1
+        assert id(1l) == (1 << 3) + 3
+        class myint(int):
+            pass
+        assert id(myint(1)) != id(1)
+
+        assert id(1.0) & 7 == 5
+        assert id(-0.0) != id(0.0)
+        assert hex(id(2.0)) == '0x20000000000000005L'
+        assert id(0.0) == 5
+
+    def test_id_on_strs(self):
+        if self.appdirect:
+            skip("cannot run this test as apptest")
+        u = u"a"
+        assert id(self.unwrap_wrap_unicode(u)) == id(u)
+        s = "a"
+        assert id(self.unwrap_wrap_str(s)) == id(s)
+
+    def test_identity_vs_id_primitives(self):
+        if self.cpython_apptest:
+            skip("cpython behaves differently")
+        import sys
+        l = range(-10, 10)
+        for i in range(10):
+            l.append(float(i))
+            l.append(i + 0.1)
+            l.append(long(i))
+            l.append(i + sys.maxint)
+            l.append(i - sys.maxint)
+            l.append(i + 1j)
+            l.append(1 + i * 1j)
+            s = str(i)
+            l.append(s)
+            u = unicode(s)
+            l.append(u)
+        l.append(-0.0)
+        l.append(None)
+        l.append(True)
+        l.append(False)
+        s = "s"
+        l.append(s)
+        s = u"s"
+        l.append(s)
+
+        for i, a in enumerate(l):
+            for b in l[i:]:
+                assert (a is b) == (id(a) == id(b))
+                if a is b:
+                    assert a == b
+
+    def test_identity_vs_id_str(self):
+        if self.appdirect:
+            skip("cannot run this test as apptest")
+        import sys
+        l = range(-10, 10)
+        for i in range(10):
+            s = str(i)
+            l.append(s)
+            l.append(self.unwrap_wrap_str(s))
+            u = unicode(s)
+            l.append(u)
+            l.append(self.unwrap_wrap_unicode(u))
+        s = "s"
+        l.append(s)
+        l.append(self.unwrap_wrap_str(s))
+        s = u"s"
+        l.append(s)
+        l.append(self.unwrap_wrap_unicode(s))
+
+        for i, a in enumerate(l):
+            for b in l[i:]:
+                assert (a is b) == (id(a) == id(b))
+                if a is b:
+                    assert a == b
+
 def test_isinstance_shortcut():
     from pypy.objspace.std import objspace
     space = objspace.StdObjSpace()
     w_a = space.wrap("a")
     space.type = None
     space.isinstance_w(w_a, space.w_str) # does not crash
-
diff --git a/pypy/objspace/std/test/test_rangeobject.py b/pypy/objspace/std/test/test_rangeobject.py
--- a/pypy/objspace/std/test/test_rangeobject.py
+++ b/pypy/objspace/std/test/test_rangeobject.py
@@ -13,7 +13,7 @@
             import __pypy__
             def f(r):
                 return (isinstance(r, list) and
-                        "W_ListObject" not in __pypy__.internal_repr(r))
+                        "RangeListStrategy" in __pypy__.internal_repr(r))
             return f
         """)
         cls.w_SORT_FORCES_LISTS = cls.space.wrap(False)
@@ -44,12 +44,9 @@
 
     def test_empty_range(self):
         r = range(10, 10)
-        if not self.SORT_FORCES_LISTS:
-            r.sort(reverse=True)
         assert len(r) == 0
         assert list(reversed(r)) == []
         assert r[:] == []
-        assert self.not_forced(r)
 
     def test_repr(self):
         r = range(5)
@@ -73,26 +70,9 @@
         r.reverse()
         assert r == [2, 1, 1]
 
-    def test_sort(self):
-        if self.SORT_FORCES_LISTS:
-            skip("sort() forces these lists")
-        r = range(10, -1, -1)
-        r.sort()
-        assert self.not_forced(r)
-        assert r == range(11)
-        r = range(11)
-        r.sort(reverse=True)
-        assert self.not_forced(r)
-        assert r == range(10, -1, -1)
-        r = range(100)
-        r[0] = 999
-        assert not self.not_forced(r)
-        r.sort()
-        assert r == range(1, 100) + [999]
         r = range(10)
         r.sort(key=lambda x: -x)
         assert r == range(9, -1, -1)
-
     def test_pop(self):
         r = range(10)
         res = r.pop()
diff --git a/pypy/objspace/std/test/test_stringobject.py b/pypy/objspace/std/test/test_stringobject.py
--- a/pypy/objspace/std/test/test_stringobject.py
+++ b/pypy/objspace/std/test/test_stringobject.py
@@ -495,7 +495,8 @@
         assert "".join([]) == ""
         assert "-".join(['a', 'b']) == 'a-b'
         text = 'text'
-        assert "".join([text]) is text
+        assert "".join([text]) == text
+        assert " -- ".join([text]) is text
         raises(TypeError, ''.join, 1)
         raises(TypeError, ''.join, [1])
         raises(TypeError, ''.join, [[1]])
diff --git a/pypy/objspace/std/test/test_strsliceobject.py b/pypy/objspace/std/test/test_strsliceobject.py
--- a/pypy/objspace/std/test/test_strsliceobject.py
+++ b/pypy/objspace/std/test/test_strsliceobject.py
@@ -110,12 +110,6 @@
         assert 'W_StringSliceObject' in __pypy__.internal_repr(s)
         assert hash(s) & 0x7fffffff == 0x7e0bce58
 
-    def test_split_produces_strslices(self):
-        import __pypy__
-        l = ("X" * 100 + "," + "Y" * 100).split(",")
-        assert "W_StringSliceObject" in __pypy__.internal_repr(l[0])
-        assert "W_StringSliceObject" in __pypy__.internal_repr(l[1])
-
     def test_strip_produces_strslices(self):
         import __pypy__
         s = ("abc" + "X" * 100 + "," + "Y" * 100 + "abc").strip("abc")
diff --git a/pypy/rlib/_rffi_stacklet.py b/pypy/rlib/_rffi_stacklet.py
--- a/pypy/rlib/_rffi_stacklet.py
+++ b/pypy/rlib/_rffi_stacklet.py
@@ -8,16 +8,21 @@
 
 cdir = py.path.local(pypydir) / 'translator' / 'c'
 
-_sep_mods = []
-if sys.platform == 'win32':
-    _sep_mods = [cdir / "src/stacklet/switch_x86_msvc.asm"]
-    
 eci = ExternalCompilationInfo(
     include_dirs = [cdir],
     includes = ['src/stacklet/stacklet.h'],
     separate_module_sources = ['#include "src/stacklet/stacklet.c"\n'],
-    separate_module_files = _sep_mods
 )
+if sys.platform == 'win32':
+    eci.separate_module_files += (cdir / "src/stacklet/switch_x86_msvc.asm", )
+    eci.export_symbols += (
+        'stacklet_newthread',
+        'stacklet_deletethread',
+        'stacklet_new',
+        'stacklet_switch',
+        'stacklet_destroy',
+        '_stacklet_translate_pointer',
+        )
 
 rffi_platform.verify_eci(eci.convert_sources_to_files())
 
diff --git a/pypy/rlib/listsort.py b/pypy/rlib/listsort.py
--- a/pypy/rlib/listsort.py
+++ b/pypy/rlib/listsort.py
@@ -10,6 +10,7 @@
 def make_timsort_class():
 
     class TimSort:
+
         """TimSort(list).sort()
 
         Sorts the list in-place, using the overridable method lt() for comparison.
@@ -551,7 +552,6 @@
             assert self.pending[0].base == 0
             assert self.pending[0].len == self.listlength
 
-
     class ListSlice:
         "A sublist of a list."
 
diff --git a/pypy/rlib/rsre/rpy.py b/pypy/rlib/rsre/rpy.py
new file mode 100644
--- /dev/null
+++ b/pypy/rlib/rsre/rpy.py
@@ -0,0 +1,49 @@
+
+from pypy.rlib.rsre import rsre_char
+from pypy.rlib.rsre.rsre_core import match
+
+def get_hacked_sre_compile(my_compile):
+    """Return a copy of the sre_compile module for which the _sre
+    module is a custom module that has _sre.compile == my_compile
+    and CODESIZE == rsre_char.CODESIZE.
+    """
+    import sre_compile, __builtin__, new
+    sre_hacked = new.module("_sre_hacked")
+    sre_hacked.compile = my_compile
+    sre_hacked.MAGIC = sre_compile.MAGIC
+    sre_hacked.CODESIZE = rsre_char.CODESIZE
+    sre_hacked.getlower = rsre_char.getlower
+    def my_import(name, *args):
+        if name == '_sre':
+            return sre_hacked
+        else:
+            return default_import(name, *args)
+    src = sre_compile.__file__
+    if src.lower().endswith('.pyc') or src.lower().endswith('.pyo'):
+        src = src[:-1]
+    mod = new.module("sre_compile_hacked")
+    default_import = __import__
+    try:
+        __builtin__.__import__ = my_import
+        execfile(src, mod.__dict__)
+    finally:
+        __builtin__.__import__ = default_import
+    return mod
+
+class GotIt(Exception):
+    pass
+def my_compile(pattern, flags, code, *args):
+    raise GotIt(code, flags, args)
+sre_compile_hacked = get_hacked_sre_compile(my_compile)
+
+def get_code(regexp, flags=0, allargs=False):
+    try:
+        sre_compile_hacked.compile(regexp, flags)
+    except GotIt, e:
+        pass
+    else:
+        raise ValueError("did not reach _sre.compile()!")
+    if allargs:
+        return e.args
+    else:
+        return e.args[0]
diff --git a/pypy/rlib/rsre/rsre_core.py b/pypy/rlib/rsre/rsre_core.py
--- a/pypy/rlib/rsre/rsre_core.py
+++ b/pypy/rlib/rsre/rsre_core.py
@@ -154,7 +154,6 @@
         return (fmarks[groupnum], fmarks[groupnum+1])
 
     def group(self, groupnum=0):
-        "NOT_RPYTHON"   # compatibility
         frm, to = self.span(groupnum)
         if 0 <= frm <= to:
             return self._string[frm:to]
diff --git a/pypy/rlib/rsre/test/test_match.py b/pypy/rlib/rsre/test/test_match.py
--- a/pypy/rlib/rsre/test/test_match.py
+++ b/pypy/rlib/rsre/test/test_match.py
@@ -1,54 +1,8 @@
 import re
-from pypy.rlib.rsre import rsre_core, rsre_char
+from pypy.rlib.rsre import rsre_core
+from pypy.rlib.rsre.rpy import get_code
 
 
-def get_hacked_sre_compile(my_compile):
-    """Return a copy of the sre_compile module for which the _sre
-    module is a custom module that has _sre.compile == my_compile
-    and CODESIZE == rsre_char.CODESIZE.
-    """
-    import sre_compile, __builtin__, new
-    sre_hacked = new.module("_sre_hacked")
-    sre_hacked.compile = my_compile
-    sre_hacked.MAGIC = sre_compile.MAGIC
-    sre_hacked.CODESIZE = rsre_char.CODESIZE
-    sre_hacked.getlower = rsre_char.getlower
-    def my_import(name, *args):
-        if name == '_sre':
-            return sre_hacked
-        else:
-            return default_import(name, *args)
-    src = sre_compile.__file__
-    if src.lower().endswith('.pyc') or src.lower().endswith('.pyo'):
-        src = src[:-1]
-    mod = new.module("sre_compile_hacked")
-    default_import = __import__
-    try:
-        __builtin__.__import__ = my_import
-        execfile(src, mod.__dict__)
-    finally:
-        __builtin__.__import__ = default_import
-    return mod
-
-class GotIt(Exception):
-    pass
-def my_compile(pattern, flags, code, *args):
-    print code
-    raise GotIt(code, flags, args)
-sre_compile_hacked = get_hacked_sre_compile(my_compile)
-
-def get_code(regexp, flags=0, allargs=False):
-    try:
-        sre_compile_hacked.compile(regexp, flags)
-    except GotIt, e:
-        pass
-    else:
-        raise ValueError("did not reach _sre.compile()!")
-    if allargs:
-        return e.args
-    else:
-        return e.args[0]
-
 def get_code_and_re(regexp):
     return get_code(regexp), re.compile(regexp)
 
diff --git a/pypy/rpython/lltypesystem/rstr.py b/pypy/rpython/lltypesystem/rstr.py
--- a/pypy/rpython/lltypesystem/rstr.py
+++ b/pypy/rpython/lltypesystem/rstr.py
@@ -316,6 +316,8 @@
         s.chars[0] = ch
         return s
 
+    @jit.look_inside_iff(lambda str: jit.isconstant(len(str)) and len(str) == 1)
+    @jit.oopspec("str.str2unicode(str)")
     def ll_str2unicode(str):
         lgt = len(str.chars)
         s = mallocunicode(lgt)
@@ -324,7 +326,6 @@
                 raise UnicodeDecodeError
             s.chars[i] = cast_primitive(UniChar, str.chars[i])
         return s
-    ll_str2unicode.oopspec = 'str.str2unicode(str)'
 
     @jit.elidable
     def ll_strhash(s):
diff --git a/pypy/rpython/rlist.py b/pypy/rpython/rlist.py
--- a/pypy/rpython/rlist.py
+++ b/pypy/rpython/rlist.py
@@ -668,6 +668,7 @@
     ll_delitem_nonneg(dum_nocheck, l, index)
     return res
 
+ at jit.look_inside_iff(lambda l: jit.isvirtual(l))
 def ll_reverse(l):
     length = l.ll_length()
     i = 0
@@ -678,7 +679,6 @@
         l.ll_setitem_fast(length_1_i, tmp)
         i += 1
         length_1_i -= 1
-ll_reverse.oopspec = 'list.reverse(l)'
 
 def ll_getitem_nonneg(func, l, index):
     ll_assert(index >= 0, "unexpectedly negative list getitem index")
diff --git a/pypy/rpython/test/test_rclass.py b/pypy/rpython/test/test_rclass.py
--- a/pypy/rpython/test/test_rclass.py
+++ b/pypy/rpython/test/test_rclass.py
@@ -457,12 +457,16 @@
                     compute_identity_hash(d))
 
         res = self.interpret(f, [])
-        # xxx this is too precise, checking the exact implementation
-        assert res.item0 == res.item1
+        # xxx the following test is too precise, checking the exact
+        # implementation.  On Python 2.7 it doesn't work anyway, because
+        # object.__hash__(x) is different from id(x).  The test is disabled
+        # for now, and nobody should rely on compute_identity_hash() returning
+        # a value that is (or was) the current_object_addr_as_int().
+        # --- disabled: assert res.item0 == res.item1
         # the following property is essential on top of the lltypesystem
         # otherwise prebuilt dictionaries are broken.  It's wrong on
         # top of the ootypesystem though.
-        if type(self) is TestLLtype:
+        if isinstance(self, LLRtypeMixin):
             assert res.item2 == h_c
             assert res.item3 == h_d
 
diff --git a/pypy/tool/jitlogparser/parser.py b/pypy/tool/jitlogparser/parser.py
--- a/pypy/tool/jitlogparser/parser.py
+++ b/pypy/tool/jitlogparser/parser.py
@@ -386,3 +386,20 @@
                                                  dump_start=start_ofs))
         loops.append(loop)
     return log, loops
+
+
+def parse_log_counts(input, loops):
+    if not input:
+        return
+    lines = input[-1].splitlines()
+    mapping = {}
+    for loop in loops:
+        com = loop.comment
+        if 'Loop' in com:
+            mapping['loop ' + re.search('Loop (\d+)', com).group(1)] = loop
+        else:
+            mapping['bridge ' + re.search('Guard (\d+)', com).group(1)] = loop
+    for line in lines:
+        if line:
+            num, count = line.split(':', 2)
+            mapping[num].count = int(count)
diff --git a/pypy/translator/platform/windows.py b/pypy/translator/platform/windows.py
--- a/pypy/translator/platform/windows.py
+++ b/pypy/translator/platform/windows.py
@@ -71,6 +71,8 @@
     so_ext = 'dll'
     exe_ext = 'exe'
 
+    relevant_environ = ('PATH', 'INCLUDE', 'LIB')
+
     cc = 'cl.exe'
     link = 'link.exe'
 
@@ -172,6 +174,12 @@
 
     def _compile_c_file(self, cc, cfile, compile_args):
         oname = cfile.new(ext='obj')
+        # notabene: (tismer)
+        # This function may be called for .c but also .asm files.
+        # The c compiler accepts any order of arguments, while
+        # the assembler still has the old behavior that all options
+        # must come first, and after the file name all options are ignored.
+        # So please be careful with the oder of parameters! ;-)
         args = ['/nologo', '/c'] + compile_args + ['/Fo%s' % (oname,), str(cfile)]
         self._execute_c_compiler(cc, args, oname)
         return oname
diff --git a/pypy/translator/simplify.py b/pypy/translator/simplify.py
--- a/pypy/translator/simplify.py
+++ b/pypy/translator/simplify.py
@@ -697,10 +697,12 @@
             if op.opname == 'getattr' and op.args[1] == c_append:
                 vlist = variable_families.find_rep(op.args[0])
                 if vlist in newlist_v:
-                    op2 = block.operations[i+1]
-                    if (op2.opname == 'simple_call' and len(op2.args) == 2
-                        and op2.args[0] is op.result):
-                        append_v.append((op.args[0], op.result, block))
+                    for j in range(i + 1, len(block.operations)):
+                        op2 = block.operations[j]
+                        if (op2.opname == 'simple_call' and len(op2.args) == 2
+                            and op2.args[0] is op.result):
+                            append_v.append((op.args[0], op.result, block))
+                            break
     if not append_v:
         return
     detector = ListComprehensionDetector(graph, loops, newlist_v,
diff --git a/pypy/translator/test/test_simplify.py b/pypy/translator/test/test_simplify.py
--- a/pypy/translator/test/test_simplify.py
+++ b/pypy/translator/test/test_simplify.py
@@ -305,6 +305,27 @@
             'hint': 2,
             })
 
+    def test_iterate_over_list(self):
+        def wrap(elem):
+            return elem
+        
+        def f(i):
+            new_l = []
+            l = range(4)
+            for elem in l:
+                new_l.append(wrap(elem))
+            return new_l
+
+        self.check(f, {
+            'hint': 2,
+            'newlist': 1,
+            'iter': 1,
+            'next': 1,
+            'getattr': 1,
+            'simple_call': 3,
+            })
+            
+
 class TestLLSpecializeListComprehension:
     typesystem = 'lltype'
 


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