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Ka-Ping Yee3bda4f02001-03-15 10:45:44 +00001"""Record of phased-in incompatible language changes.
Tim Petersffc215a2001-02-26 21:14:49 +00002
3Each line is of the form:
4
Tim Petersde642bd2001-08-17 19:49:02 +00005 FeatureName = "_Feature(" OptionalRelease "," MandatoryRelease ","
6 CompilerFlag ")"
Tim Petersffc215a2001-02-26 21:14:49 +00007
8where, normally, OptionalRelease < MandatoryRelease, and both are 5-tuples
9of the same form as sys.version_info:
10
11 (PY_MAJOR_VERSION, # the 2 in 2.1.0a3; an int
12 PY_MINOR_VERSION, # the 1; an int
13 PY_MICRO_VERSION, # the 0; an int
14 PY_RELEASE_LEVEL, # "alpha", "beta", "candidate" or "final"; string
15 PY_RELEASE_SERIAL # the 3; an int
16 )
17
18OptionalRelease records the first release in which
19
20 from __future__ import FeatureName
21
22was accepted.
23
Tim Peters85ba6732001-02-28 08:26:44 +000024In the case of MandatoryReleases that have not yet occurred,
25MandatoryRelease predicts the release in which the feature will become part
Tim Petersffc215a2001-02-26 21:14:49 +000026of the language.
27
Tim Peters85ba6732001-02-28 08:26:44 +000028Else MandatoryRelease records when the feature became part of the language;
Tim Petersffc215a2001-02-26 21:14:49 +000029in releases at or after that, modules no longer need
30
31 from __future__ import FeatureName
32
33to use the feature in question, but may continue to use such imports.
34
Tim Peters85ba6732001-02-28 08:26:44 +000035MandatoryRelease may also be None, meaning that a planned feature got
Tim Petersffc215a2001-02-26 21:14:49 +000036dropped.
37
Tim Petersd74bc432001-03-02 02:53:08 +000038Instances of class _Feature have two corresponding methods,
39.getOptionalRelease() and .getMandatoryRelease().
40
Tim Petersde642bd2001-08-17 19:49:02 +000041CompilerFlag is the (bitfield) flag that should be passed in the fourth
42argument to the builtin function compile() to enable the feature in
43dynamically compiled code. This flag is stored in the .compiler_flag
44attribute on _Future instances. These values must match the appropriate
45#defines of CO_xxx flags in Include/compile.h.
46
Tim Petersd74bc432001-03-02 02:53:08 +000047No feature line is ever to be deleted from this file.
Tim Petersffc215a2001-02-26 21:14:49 +000048"""
49
Tim Petersde642bd2001-08-17 19:49:02 +000050all_feature_names = [
51 "nested_scopes",
52 "generators",
53 "division",
Thomas Woutersf7f438b2006-02-28 16:09:29 +000054 "absolute_import",
Thomas Wouters34aa7ba2006-02-28 19:02:24 +000055 "with_statement",
Tim Petersde642bd2001-08-17 19:49:02 +000056]
57
58__all__ = ["all_feature_names"] + all_feature_names
59
Tim Peters89675072001-08-24 06:29:12 +000060# The CO_xxx symbols are defined here under the same names used by
61# compile.h, so that an editor search will find them here. However,
62# they're not exported in __all__, because they don't really belong to
63# this module.
64CO_NESTED = 0x0010 # nested_scopes
Neal Norwitz0023a2f2006-02-27 23:24:48 +000065CO_GENERATOR_ALLOWED = 0 # generators (obsolete, was 0x1000)
Tim Peters89675072001-08-24 06:29:12 +000066CO_FUTURE_DIVISION = 0x2000 # division
Thomas Wouters49fd7fa2006-04-21 10:40:58 +000067CO_FUTURE_ABSOLUTE_IMPORT = 0x4000 # perform absolute imports by default
Neal Norwitz91934912006-02-28 20:02:42 +000068CO_FUTURE_WITH_STATEMENT = 0x8000 # with statement
Tim Petersde642bd2001-08-17 19:49:02 +000069
Tim Petersd74bc432001-03-02 02:53:08 +000070class _Feature:
Tim Petersde642bd2001-08-17 19:49:02 +000071 def __init__(self, optionalRelease, mandatoryRelease, compiler_flag):
Tim Petersd74bc432001-03-02 02:53:08 +000072 self.optional = optionalRelease
73 self.mandatory = mandatoryRelease
Tim Petersde642bd2001-08-17 19:49:02 +000074 self.compiler_flag = compiler_flag
Tim Petersd74bc432001-03-02 02:53:08 +000075
76 def getOptionalRelease(self):
77 """Return first release in which this feature was recognized.
78
79 This is a 5-tuple, of the same form as sys.version_info.
80 """
81
82 return self.optional
83
84 def getMandatoryRelease(self):
85 """Return release in which this feature will become mandatory.
86
87 This is a 5-tuple, of the same form as sys.version_info, or, if
88 the feature was dropped, is None.
89 """
90
91 return self.mandatory
92
93 def __repr__(self):
Tim Peters16c018d2001-08-24 17:13:54 +000094 return "_Feature" + repr((self.optional,
95 self.mandatory,
96 self.compiler_flag))
Tim Petersd74bc432001-03-02 02:53:08 +000097
Tim Petersde642bd2001-08-17 19:49:02 +000098nested_scopes = _Feature((2, 1, 0, "beta", 1),
99 (2, 2, 0, "alpha", 0),
Tim Peters89675072001-08-24 06:29:12 +0000100 CO_NESTED)
Tim Petersde642bd2001-08-17 19:49:02 +0000101
102generators = _Feature((2, 2, 0, "alpha", 1),
103 (2, 3, 0, "final", 0),
Tim Peters89675072001-08-24 06:29:12 +0000104 CO_GENERATOR_ALLOWED)
Tim Petersde642bd2001-08-17 19:49:02 +0000105
106division = _Feature((2, 2, 0, "alpha", 2),
107 (3, 0, 0, "alpha", 0),
Tim Peters89675072001-08-24 06:29:12 +0000108 CO_FUTURE_DIVISION)
Thomas Woutersf7f438b2006-02-28 16:09:29 +0000109
110absolute_import = _Feature((2, 5, 0, "alpha", 1),
111 (2, 7, 0, "alpha", 0),
Thomas Wouters49fd7fa2006-04-21 10:40:58 +0000112 CO_FUTURE_ABSOLUTE_IMPORT)
Thomas Wouters34aa7ba2006-02-28 19:02:24 +0000113
Neal Norwitz91934912006-02-28 20:02:42 +0000114with_statement = _Feature((2, 5, 0, "alpha", 1),
Thomas Wouters34aa7ba2006-02-28 19:02:24 +0000115 (2, 6, 0, "alpha", 0),
116 CO_FUTURE_WITH_STATEMENT)