[pypy-commit] pypy stacklet: API and comments describing the goal of the refactoring I'm starting now.

[arigo]

Author: Armin Rigo <arigo at tunes.org>
Branch: stacklet
Changeset: r46558:17ff11cb0bc1
Date: 2011-08-17 12:42 +0200
http://bitbucket.org/pypy/pypy/changeset/17ff11cb0bc1/

Log:	API and comments describing the goal of the refactoring I'm starting
	now.

diff --git a/pypy/module/_continuation/__init__.py b/pypy/module/_continuation/__init__.py
--- a/pypy/module/_continuation/__init__.py
+++ b/pypy/module/_continuation/__init__.py
@@ -2,16 +2,25 @@
 
 
 class Module(MixedModule):
-    """
-    This module exposes 'continuations'.
-    """
+    """This module exposes 'one-shot continuation containers'.
+
+A 'flexibleframe' object from this module is a container that stores a
+one-shot continuation.  It is a frame-like object, attached as the
+'f_back' of the entry point function that it calls, and with an 'f_back'
+of its own.  Unlike normal frames, the continuation exposed in this
+'f_back' can be changed, with the switch() and switch2() methods.
+
+Flexible frames are internally implemented using stacklets.  Stacklets
+are a bit more primitive (they are one-shot continuations, usable only
+once) but that concept only really works in C, not in Python, notably
+because of exceptions.
+"""
 
     appleveldefs = {
         'error': 'app_continuation.error',
+        'generator': 'app_continuation.generator',
     }
 
     interpleveldefs = {
-        'new': 'interp_continuation.stacklet_new',
-        'callcc': 'interp_continuation.stacklet_new',     # a synonym
-        'Continuation': 'interp_continuation.W_Stacklet',
+        'flexibleframe': 'interp_continuation.W_FlexibleFrame',
     }
diff --git a/pypy/module/_continuation/app_continuation.py b/pypy/module/_continuation/app_continuation.py
--- a/pypy/module/_continuation/app_continuation.py
+++ b/pypy/module/_continuation/app_continuation.py
@@ -1,4 +1,33 @@
-
 
 class error(Exception):
     "Usage error of the _continuation module."
+
+
+from _continuation import flexibleframe
+
+
+class generator(object):
+
+    def __init__(self, callable):
+        self.__func__ = callable
+
+    def __get__(self, obj, type=None):
+        return generator(self.__func__.__get__(obj, type))
+
+    def __call__(self, *args, **kwds):
+        return genlet(self.__func__, *args, **kwds)
+
+
+class genlet(flexibleframe):
+
+    def __iter__(self):
+        return self
+
+    def next(self, value=None):
+        res = self.switch(value)
+        if self.is_alive():
+            return res
+        else:
+            raise StopIteration
+
+    send = next