def walk_function(self, formula, args, **kwargs):
from pysmt.typing import FunctionType
# Separate arguments
bool_args = []
other_args = []
for a in args:
if self.get_type(a).is_bool_type():
bool_args.append(a)
else:
other_args.append(a)
if len(bool_args) == 0:
# If no Bool Args, return as-is
return IdentityDagWalker.walk_function(self, formula, args, **kwargs)
# Build new function type
rtype = formula.function_name().symbol_type().return_type
ptype = [self.get_type(a) for a in other_args]
if len(ptype) == 0:
ftype = rtype
else:
ftype = FunctionType(rtype, ptype)
# Base-case
stack = []
for i in xrange(2**len(bool_args)):
fname = self.mgr.Symbol("%s#%i" % (formula.function_name(),i), ftype)
if len(ptype) == 0:
stack.append(fname)
else:
stack.append(self.mgr.Function(fname, tuple(other_args)))
# Recursive case
for b in bool_args:
tmp = []
while len(stack) > 0:
lhs = stack.pop()
rhs = stack.pop()
# Simplify branches, if b is a constant
if b.is_true():
tmp.append(lhs)
elif b.is_false():
tmp.append(rhs)
else:
ite = self.mgr.Ite(b, lhs, rhs)
tmp.append(ite)
stack = tmp
res = stack[0]
return res
