mapnik/scons/scons-local-0.97.0d20071212/SCons/Options/BoolOption.py
2008-02-07 09:59:49 +00:00

86 lines
2.9 KiB
Python

"""engine.SCons.Options.BoolOption
This file defines the option type for SCons implementing true/false values.
Usage example:
opts = Options()
opts.Add(BoolOption('embedded', 'build for an embedded system', 0))
...
if env['embedded'] == 1:
...
"""
#
# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007 The SCons Foundation
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#
__revision__ = "src/engine/SCons/Options/BoolOption.py 2523 2007/12/12 09:37:41 knight"
__all__ = ('BoolOption')
import string
import SCons.compat
import SCons.Errors
__true_strings = ('y', 'yes', 'true', 't', '1', 'on' , 'all' )
__false_strings = ('n', 'no', 'false', 'f', '0', 'off', 'none')
def _text2bool(val):
"""
Converts strings to True/False depending on the 'truth' expressed by
the string. If the string can't be converted, the original value
will be returned.
See '__true_strings' and '__false_strings' for values considered
'true' or 'false respectivly.
This is usable as 'converter' for SCons' Options.
"""
lval = string.lower(val)
if lval in __true_strings: return True
if lval in __false_strings: return False
raise ValueError("Invalid value for boolean option: %s" % val)
def _validator(key, val, env):
"""
Validates the given value to be either '0' or '1'.
This is usable as 'validator' for SCons' Options.
"""
if not env[key] in (True, False):
raise SCons.Errors.UserError(
'Invalid value for boolean option %s: %s' % (key, env[key]))
def BoolOption(key, help, default):
"""
The input parameters describe a boolen option, thus they are
returned with the correct converter and validator appended. The
'help' text will by appended by '(yes|no) to show the valid
valued. The result is usable for input to opts.Add().
"""
return (key, '%s (yes|no)' % help, default,
_validator, _text2bool)