[pypy-svn] r69516 - pypy/trunk/pypy/objspace/std

[fijal at codespeak.net]

Author: fijal
Date: Sun Nov 22 23:37:20 2009
New Revision: 69516

Modified:
   pypy/trunk/pypy/objspace/std/unicodeobject.py
Log:
improve join on unicode


Modified: pypy/trunk/pypy/objspace/std/unicodeobject.py
==============================================================================
--- pypy/trunk/pypy/objspace/std/unicodeobject.py	(original)
+++ pypy/trunk/pypy/objspace/std/unicodeobject.py	Sun Nov 22 23:37:20 2009
@@ -13,6 +13,7 @@
 
 from pypy.objspace.std.formatting import mod_format
 from pypy.objspace.std.stringtype import stringstartswith, stringendswith
+from pypy.rlib.rstring import UnicodeBuilder
 
 class W_UnicodeObject(W_Object):
     from pypy.objspace.std.unicodetype import unicode_typedef as typedef
@@ -174,29 +175,38 @@
     return space.newbool(container.find(item) != -1)
 
 def unicode_join__Unicode_ANY(space, w_self, w_list):
-    l = space.listview(w_list)
+    l_w = space.listview(w_list)
     delim = w_self._value
-    totlen = 0
-    if len(l) == 0:
+    if len(l_w) == 0:
         return W_UnicodeObject.EMPTY
-    if (len(l) == 1 and
-        space.is_w(space.type(l[0]), space.w_unicode)):
-        return l[0]
-    
-    values_list = [None] * len(l)
-    for i in range(len(l)):
-        item = l[i]
-        if isinstance(item, W_UnicodeObject):
+    if (len(l_w) == 1 and
+        space.is_w(space.type(l_w[0]), space.w_unicode)):
+        return l_w[0]
+    lgt = 0
+    for i in range(len(l_w)):
+        w_item = l_w[i]
+        if isinstance(w_item, W_UnicodeObject):
             # shortcut for performane
-            item = item._value
-        elif space.is_true(space.isinstance(item, space.w_str)):
-            item = space.unicode_w(item)
+            lgt += len(w_item._value)
+        elif space.is_true(space.isinstance(w_item, space.w_str)):
+            lgt += len(space.str_w(w_item))
+            # some estimate, does not need to be perfect
         else:
             w_msg = space.mod(space.wrap('sequence item %d: expected string or Unicode'),
                               space.wrap(i))
             raise OperationError(space.w_TypeError, w_msg)
-        values_list[i] = item
-    return W_UnicodeObject(w_self._value.join(values_list))
+    # now we know it's a list of unicode or string
+    lgt += len(delim) * (len(l_w) - 1)
+    builder = UnicodeBuilder(lgt)
+    for i in range(len(l_w)):
+        w_item = l_w[i]
+        if isinstance(w_item, W_UnicodeObject):
+            builder.append(w_item._value)
+        else:
+            builder.append(space.unicode_w(w_item))
+        if i != len(l_w) - 1:
+            builder.append(delim)
+    return W_UnicodeObject(builder.build())
 
 def hash__Unicode(space, w_uni):
     s = w_uni._value