1 """engine.SCons.Variables.BoolVariable
2
3 This file defines the option type for SCons implementing true/false values.
4
5 Usage example:
6
7 opts = Variables()
8 opts.Add(BoolVariable('embedded', 'build for an embedded system', 0))
9 ...
10 if env['embedded'] == 1:
11 ...
12 """
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37 __revision__ = "src/engine/SCons/Variables/BoolVariable.py rel_2.4.0:3365:9259ea1c13d7 2015/09/21 14:03:43 bdbaddog"
38
39 __all__ = ['BoolVariable',]
40
41 import SCons.Errors
42
43 __true_strings = ('y', 'yes', 'true', 't', '1', 'on' , 'all' )
44 __false_strings = ('n', 'no', 'false', 'f', '0', 'off', 'none')
45
46
48 """
49 Converts strings to True/False depending on the 'truth' expressed by
50 the string. If the string can't be converted, the original value
51 will be returned.
52
53 See '__true_strings' and '__false_strings' for values considered
54 'true' or 'false respectivly.
55
56 This is usable as 'converter' for SCons' Variables.
57 """
58 lval = val.lower()
59 if lval in __true_strings: return True
60 if lval in __false_strings: return False
61 raise ValueError("Invalid value for boolean option: %s" % val)
62
63
65 """
66 Validates the given value to be either '0' or '1'.
67
68 This is usable as 'validator' for SCons' Variables.
69 """
70 if not env[key] in (True, False):
71 raise SCons.Errors.UserError(
72 'Invalid value for boolean option %s: %s' % (key, env[key]))
73
74
76 """
77 The input parameters describe a boolen option, thus they are
78 returned with the correct converter and validator appended. The
79 'help' text will by appended by '(yes|no) to show the valid
80 valued. The result is usable for input to opts.Add().
81 """
82 return (key, '%s (yes|no)' % help, default,
83 _validator, _text2bool)
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