(Code contributed by Jiwon Seo.)
The documentation portion of the patch is being re-worked and will be
checked-in soon. Likewise, PEP 289 will be updated to reflect Guido's
rationale for the design decisions on binding behavior (as described in
in his patch comments and in discussions on python-dev).
The test file, test_genexps.py, is written in doctest format and is
meant to exercise all aspects of the the patch. Further additions are
welcome from everyone. Please stress test this new feature as much as
possible before the alpha release.
The compiler was reseting the list comprehension tmpname counter for each function, but the symtable was using the same counter for the entire module. Repair by move tmpname into the symtable entry.
Bugfix candidate.
Makefile.pre.in: add target future.o
Include/compile.h: define PyFutureFeaters and PyNode_Future()
add c_future slot to struct compiling
Include/symtable.h: add st_future slot to struct symtable
Python/future.c: implementation of PyNode_Future()
Python/compile.c: use PyNode_Future() for nested_scopes support
Python/symtable.c: include compile.h to pick up PyFutureFeatures decl
compile.h: #define NESTED_SCOPES_DEFAULT 0 for Python 2.1
__future__ feature name: "nested_scopes"
symtable.h: Add st_nested_scopes slot. Define flags to track exec and
import star.
Lib/test/test_scope.py: requires nested scopes
compile.c: Fiddle with error messages.
Reverse the sense of ste_optimized flag on
PySymtableEntryObjects. If it is true, there is an optimization
conflict.
Modify get_ref_type to respect st_nested_scopes flags.
Refactor symtable_load_symbols() into several smaller functions,
which use struct symbol_info to share variables. In new function
symtable_update_flags(), raise an error or warning for import * or
bare exec that conflicts with nested scopes. Also, modify handle
for free variables to respect st_nested_scopes flag.
In symtable_init() assign st_nested_scopes flag to
NESTED_SCOPES_DEFAULT (defined in compile.h).
Add preliminary and often incorrect implementation of
symtable_check_future().
Add symtable_lookup() helper for future use.
of nested functions. Either is allowed in a function if it contains
no defs or lambdas or the defs and lambdas it contains have no free
variables. If a function is itself nested and has free variables,
either is illegal.
Revise the symtable to use a PySymtableEntryObject, which holds all
the revelent information for a scope, rather than using a bunch of
st_cur_XXX pointers in the symtable struct. The changes simplify the
internal management of the current symtable scope and of the stack.
Added new C source file: Python/symtable.c. (Does the Windows build
process need to be updated?)
As part of these changes, the initial _symtable module interface
introduced in 2.1a2 is replaced. A dictionary of
PySymtableEntryObjects are returned.
symtable.h, so that they can be used by external module.
Improve error handling in symtable_enter_scope(), which return an
error code that went unchecked by most callers. XXX The error handling
in symtable code is sloppy in general.
Modify symtable to record the line number that begins each scope.
This can help to identify which code block is being referred to when
multiple blocks are bound to the same name.
Add st_scopes dict that is used to preserve scope info when
PyNode_CompileSymtable() is called. Otherwise, this information is
tossed as soon as it is no longer needed.
Add Py_SymtableString() to pythonrun; analogous to Py_CompileString().
Raymond Hettinger
Jeremy Hylton
Martin v. Löwis
Mark Hammond
Tim Peters