(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 old syntax suggested that a trailing comma was OK inside backticks,
but in fact (due to ideosyncrasies of pgen) it was not. Fix the grammar
to avoid the ambiguity. Fred: you may want to update the refman.
"for <var> in <testlist> may no longer be a single test followed by
a comma. This solves SF bug #431886. Note that if the testlist
contains more than one test, a trailing comma is still allowed, for
maximum backward compatibility; but this example is not:
[(x, y) for x in range(10), for y in range(10)]
^
The fix involved creating a new nonterminal 'testlist_safe' whose
definition doesn't allow the trailing comma if there's only one test:
testlist_safe: test [(',' test)+ [',']]
name as n'. By doing some twists and turns, "as" is not a reserved word.
There is a slight change in semantics for 'from module import name' (it will
now honour the 'global' keyword) but only in cases that are explicitly
undocumented.
* funcobject.c (func_repr): don't call getstringvalue(None) for anonymous
functions.
* bltinmodule.c: removed lambda (which is now a built-in function);
removed implied lambda for string arg to filter/map/reduce.
* Grammar, graminit.[ch], compile.[ch]: replaced lambda as built-in
function by lambda as grammar entity: instead of "lambda('x: x+1')" you
write "lambda x: x+1".
* Xtmodule.c (checkargdict): return 0, not NULL, for error.
* PROTO.h, mymalloc.h: added #ifdefs for TURBOC and GNUC.
* allobjects.h: added #include "rangeobject.h"
* Grammar: added lambda_input; relaxed syntax for exec.
* bltinmodule.c: added bagof, map, reduce, lambda, xrange.
* tupleobject.[ch]: added resizetuple().
* rangeobject.[ch]: new object type to speed up range operations (not
convinced this is needed!!!)
* Grammar: add exec statement; allow testlist in expr statement.
* ceval.c, compile.c, opcode.h: support exec statement;
avoid optimizing locals when it is used
* fileobject.{c,h}: add getfilename() internal function.
(1) dictionaries/mappings now have attributes values() and items() as
well as keys(); at the C level, use the new function mappinggetnext()
to iterate over a dictionary.
(2) "class C(): ..." is now illegal; you must write "class C: ...".
(3) Class objects now know their own name (finally!); and minor
improvements to the way how classes, functions and methods are
represented as strings.
(4) Added an "access" statement and semantics. (This is still
experimental -- as long as you don't use the keyword 'access' nothing
should be changed.)
Anthony Baxter
Raymond Hettinger
Martin v. Löwis
Guido van Rossum
Tim Peters
Thomas Wouters
Skip Montanaro