Merged revisions 61209-61214,61217-61222,61224-61226,61233-61237 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

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  r61209 | georg.brandl | 2008-03-03 21:37:55 +0100 (Mon, 03 Mar 2008) | 2 lines

  There are now sixteen isfoo functions.
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  r61210 | georg.brandl | 2008-03-03 21:39:00 +0100 (Mon, 03 Mar 2008) | 2 lines

  15 -> 16, the 2nd
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  r61211 | georg.brandl | 2008-03-03 22:22:47 +0100 (Mon, 03 Mar 2008) | 2 lines

  Actually import itertools.
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  r61212 | georg.brandl | 2008-03-03 22:31:50 +0100 (Mon, 03 Mar 2008) | 2 lines

  Expand a bit on genexp scopes.
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  r61213 | raymond.hettinger | 2008-03-03 23:04:55 +0100 (Mon, 03 Mar 2008) | 1 line

  Remove dependency on itertools -- a simple genexp suffices.
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  r61214 | raymond.hettinger | 2008-03-03 23:19:58 +0100 (Mon, 03 Mar 2008) | 1 line

  Issue 2226: Callable checked for the wrong abstract method.
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  r61217 | andrew.kuchling | 2008-03-04 01:40:32 +0100 (Tue, 04 Mar 2008) | 1 line

  Typo fix
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  r61218 | andrew.kuchling | 2008-03-04 02:30:10 +0100 (Tue, 04 Mar 2008) | 1 line

  Grammar fix; markup fix
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  r61219 | andrew.kuchling | 2008-03-04 02:47:38 +0100 (Tue, 04 Mar 2008) | 1 line

  Fix sentence fragment
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  r61220 | andrew.kuchling | 2008-03-04 02:48:26 +0100 (Tue, 04 Mar 2008) | 1 line

  Typo fix
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  r61221 | andrew.kuchling | 2008-03-04 02:49:37 +0100 (Tue, 04 Mar 2008) | 1 line

  Add versionadded tags
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  r61222 | andrew.kuchling | 2008-03-04 02:50:32 +0100 (Tue, 04 Mar 2008) | 1 line

  Thesis night results: add various items
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  r61224 | raymond.hettinger | 2008-03-04 05:17:08 +0100 (Tue, 04 Mar 2008) | 1 line

  Beef-up docs and tests for itertools.  Fix-up end-case for product().
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  r61225 | georg.brandl | 2008-03-04 08:25:54 +0100 (Tue, 04 Mar 2008) | 2 lines

  Fix some patch attributions.
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  r61226 | georg.brandl | 2008-03-04 08:33:30 +0100 (Tue, 04 Mar 2008) | 2 lines

  #2230: document that PyArg_* leaves addresses alone on error.
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  r61233 | neal.norwitz | 2008-03-04 17:22:46 +0100 (Tue, 04 Mar 2008) | 3 lines

  Close the file before trying to remove the directory so it works on Windows.
  As reported by Trent Nelson on python-dev.
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  r61234 | thomas.heller | 2008-03-04 21:09:11 +0100 (Tue, 04 Mar 2008) | 9 lines

  Merged changes from libffi3-branch.

  The bundled libffi copy is now in sync with the recently released
  libffi3.0.4 version, apart from some small changes to
  Modules/_ctypes/libffi/configure.ac.

  I gave up on using libffi3 files on os x.
  Instead, static configuration with files from pyobjc is used.
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  r61235 | thomas.heller | 2008-03-04 21:21:42 +0100 (Tue, 04 Mar 2008) | 1 line

  Try to fix the build for PY_LINUX.
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  r61236 | fred.drake | 2008-03-04 22:14:04 +0100 (Tue, 04 Mar 2008) | 2 lines

  fix typo
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  r61237 | raymond.hettinger | 2008-03-04 23:29:44 +0100 (Tue, 04 Mar 2008) | 1 line

  Fix refleak in chain().
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1 files changed, 14 insertions, 0 deletions

diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
index e8efa9f..ac3c90f 100644
--- a/Doc/reference/expressions.rst
+++ b/Doc/reference/expressions.rst
@@ -232,6 +232,20 @@ and added to the set object.  When a comprehension is supplied, the set is
 constructed from the elements resulting from the comprehension.
 
 
+Variables used in the generator expression are evaluated lazily in a separate
+scope when the :meth:`next` method is called for the generator object (in the
+same fashion as for normal generators).  However, the :keyword:`in` expression
+of the leftmost :keyword:`for` clause is immediately evaluated in the current
+scope so that an error produced by it can be seen before any other possible
+error in the code that handles the generator expression.  Subsequent
+:keyword:`for` and :keyword:`if` clauses cannot be evaluated immediately since
+they may depend on the previous :keyword:`for` loop.  For example:
+``(x*y for x in range(10) for y in bar(x))``.
+
+The parentheses can be omitted on calls with only one argument. See section
+:ref:`calls` for the detail.
+
+
 .. _dict:
 
 Dictionary displays