def test_parse_variable_type(self):
assert qtype.is_variable(self.parser.parse_type('?a'))
fun = self.parser.parse_type('?a->?a')
assert fun.args[0] == fun.args[1]
fun = self.parser.parse_type('?a->?b')
assert fun.args[0] != fun.args[1]
fun2 = self.parser.parse_type('?a->?b')
assert fun.args[0] != fun2.args[0]
assert fun.args[1] != fun2.args[1]
def build_combination(self, operator, operand):
if qtype.is_variable(operator.qtype):
operator = operator.substitute_type(qtype.qfun(operand.qtype, qtype.qvar()), operator.qtype)
if operator.qtype.name != "fun":
raise TypeError("operators must be functions")
unifier = qtype_unifier.TypeUnifier()
unifier.unify(operator.qtype.args[0], operand.qtype)
for key, value in unifier.get_substitutions().iteritems():
operator = operator.substitute_type(value, key)
operand = operand.substitute_type(value, key)
operator, operand = unify_types([operator, operand])
if operator.qtype.args[0] != operand.qtype:
raise TypeError("operand type must match operator argument type")
return qterm.Combination(operator, operand)
def test_parse_untyped_variable(self):
var = self.parser.parse('var')
assert var.name == 'var'
assert qtype.is_variable(var.qtype)
