# pylint: disable=W0611
#
# Copyright (c) 2003-2010 LOGILAB S.A. (Paris, FRANCE).
# http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This program is free software; you can redistribute it and/or modify it under
# the terms of the GNU General Public License as published by the Free Software
# Foundation; either version 2 of the License, or (at your option) any later
# version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License along with
# this program; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
"""some functions that may be useful for various checkers
"""

import string
from logilab import astng
from logilab.common.compat import builtins
BUILTINS_NAME = builtins.__name__

COMP_NODE_TYPES = astng.ListComp, astng.SetComp, astng.DictComp, astng.GenExpr

def safe_infer(node):
    """return the inferred value for the given node.
    Return None if inference failed or if there is some ambiguity (more than
    one node has been inferred)
    """
    try:
        inferit = node.infer()
        value = inferit.next()
    except astng.InferenceError:
        return
    try:
        inferit.next()
        return # None if there is ambiguity on the inferred node
    except StopIteration:
        return value

def is_super(node):
    """return True if the node is referencing the "super" builtin function
    """
    if getattr(node, 'name', None) == 'super' and \
           node.root().name == BUILTINS_NAME:
        return True