def handle_iif(expr, split_expr, dictionary):
""" create the 4 rules related to the iif expression """
symb = "=>"
not_cdt = "!(%s)" % split_expr[0]
not_cc = "!(%s)" % split_expr[2]
rules = []
rules.append(Rule(expr, [split_expr[0], symb, split_expr[2]], dictionary))
rules.append(Rule(expr, [not_cdt, symb, not_cc], dictionary))
rules.append(Rule(expr, [split_expr[2], symb, split_expr[0]], dictionary))
rules.append(Rule(expr, [not_cc, symb, not_cdt], dictionary))
return rules
def create_rule(expr, dictionary):
""" create a list of Rule object with all the rules needed to resolve the
given expression
"""
split = split_expr(expr)
if None in split:
error(-1)
if '<' in split[1]:
rules = handle_iif(expr, split, dictionary)
else:
rules = [Rule(expr, split, dictionary)]
if td.Error in rules:
error(-1)
return rules