source: SHX/trunk/src/SeismicHandler/commands/sdef.py @ 244

# -*- coding: utf-8 -*-

#    This file is part of Seismic Handler eXtended (SHX).
#
#    SHX is free software: you can redistribute it and/or modify
#    it under the terms of the GNU Lesser General Public License as published
#    by the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    SHX is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU Lesser General Public License for more details.
#
#    You should have received a copy of the GNU Lesser General Public License
#    along with SHX.  If not, see <http://www.gnu.org/licenses/>.

from SeismicHandler.core.command import BaseCommand
from SeismicHandler.core import Settings

provides = {"sdef": "sdef"}
class sdef(BaseCommand):
    """
    Defines local and global symbols (variables). If a seconds parameter is
    entered the new symbol is initialized with this value.

    This command deals with the local and/or global symbol set. This is defined
    a parser level, for doctest is has to done manually.
    >>> from SeismicHandler.core.parser import symbol
    >>> s = symbol()

    Define a local symbol:
    >>> _ = sdef("foo", 1, shx_symbols=s)
    >>> s.foo
    1

    Don't overwrite a already present symbol:
    >>> _ = sdef("foo", 2, shx_qualifiers={"CHECK": True}, shx_symbols=s)
    >>> s.foo
    1

    A global symbol needs a qualifier:
    >>> _ = sdef("bar", 3, shx_qualifiers={"GLOBAL": True}, shx_symbols=s)
    >>> s.bar
    3

    Defining an identically local symbol masks the global one:
    >>> _ = sdef("bar", 4, shx_symbols=s)
    >>> s.bar
    4

    If we initialize another symbol set, the globally defined symbols should
    be still there:
    >>> s1 = symbol()
    >>> s1.bar
    3

    URI:http://www.seismic-handler.org/portal/wiki/ShDef
    """
    numberOfParameters = [1, 2]
    known_qualifiers = [
        "CHECK",
        "REPLACE",
        "GLOBAL",
    ]
    expectFilename = False

    def __init__(self, *args, **kwargs):
        # unroll args & kwargs
        BaseCommand.__init__(self, *args, **kwargs)

    def run(self):
        # Don't change symbol if already present
        if self.qualifiers["CHECK"]:
            try:
                _ = getattr(self.symbols, self.parameters[0])
            except KeyError:
                pass
            else:
                return

        if self.qualifiers["GLOBAL"]:
            self.symbols.setGlobal(*self.parameters)
        else:
            try:
                value = self.parameters[1]
            except:
                value = None
                
            setattr(self.symbols, self.parameters[0], value)

if __name__ == "__main__":
    import doctest
    doctest.testmod(exclude_empty=True)