# MIT License
#
# Copyright 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.
"""Variable type for true/false Variables.
Usage example::
opts = Variables()
opts.Add(BoolVariable('embedded', 'build for an embedded system', 0))
...
if env['embedded'] == 1:
...
"""
from typing import Tuple, Callable
import SCons.Errors
__all__ = ['BoolVariable',]
TRUE_STRINGS = ('y', 'yes', 'true', 't', '1', 'on' , 'all')
FALSE_STRINGS = ('n', 'no', 'false', 'f', '0', 'off', 'none')
[docs]def _text2bool(val) -> bool:
"""Converts strings to True/False.
If *val* looks like it expresses a bool-like value, based on
the :data:`TRUE_STRINGS` and :data:`FALSE_STRINGS` tuples,
return the appropriate value.
This is usable as a converter function for SCons Variables.
Raises:
ValueError: if the string cannot be converted.
"""
lval = val.lower()
if lval in TRUE_STRINGS:
return True
if lval in FALSE_STRINGS:
return False
raise ValueError("Invalid value for boolean option: %s" % val)
[docs]def _validator(key, val, env) -> None:
"""Validates the given value to be either true or false.
This is usable as a validator function for SCons Variables.
Raises:
KeyError: if key is not set in env
UserError: if key does not validate.
"""
if not env[key] in (True, False):
raise SCons.Errors.UserError(
'Invalid value for boolean option %s: %s' % (key, env[key])
)
[docs]def BoolVariable(key, help, default) -> Tuple[str, str, str, Callable, Callable]:
"""Return a tuple describing a boolean SCons Variable.
The input parameters describe a boolean option. Returns a tuple
including the correct converter and validator.
The *help* text will have ``(yes|no)`` automatically appended to show the
valid values. The result is usable as input to :meth:`Add`.
"""
help = '%s (yes|no)' % help
return (key, help, default, _validator, _text2bool)
# Local Variables:
# tab-width:4
# indent-tabs-mode:nil
# End:
# vim: set expandtab tabstop=4 shiftwidth=4: