def test_parse_clauses_one():
clause_str = 'p(x, y) :- p(x, z), q(z, a), r(a, y)'
parsed = clauses.grammar.parse(clause_str)
clause = clauses.ClauseVisitor().visit(parsed)
assert isinstance(clause, clauses.Clause)
assert isinstance(clause.head, clauses.Atom)
assert isinstance(clause.body, tuple)
assert isinstance(clause.head.predicate, clauses.Predicate)
assert isinstance(clause.head.arguments, tuple)
assert isinstance(clause.head.negated, bool)
assert clause.weight == 1.0
def test_parse_atom_clause():
clause_str = 'p(X, y)'
parsed = clauses.grammar.parse(clause_str)
clause = clauses.ClauseVisitor().visit(parsed)
assert isinstance(clause, clauses.Clause)
assert isinstance(clause.head, clauses.Atom)
assert len(clause.body) == 0
assert clause.head.predicate.name == "p"
assert isinstance(clause.head.arguments[0], clauses.Variable)
assert isinstance(clause.head.arguments[1], clauses.Constant)
assert clause.head.arguments[1].name == "y"
assert clause.weight == 1.0
def test_parse_learnable_weight_atom_clause():
clause_str = 'p(X, y) < ? >'
parsed = clauses.grammar.parse(clause_str)
clause = clauses.ClauseVisitor().visit(parsed)
assert clause.weight is None
def test_parse_weighted_arity_2_clause():
clause_str = 'p(X, y) :- r(X,Z), q(X) < 1.2 >'
parsed = clauses.grammar.parse(clause_str)
clause = clauses.ClauseVisitor().visit(parsed)
assert clause.weight == 1.2
def test_parse_weighted_atom_clause():
clause_str = 'p(X, y) < -1.2 >'
parsed = clauses.grammar.parse(clause_str)
clause = clauses.ClauseVisitor().visit(parsed)
assert clause.weight == -1.2
def parse_clause(text):
parsed = clauses.grammar.parse(text)
return clauses.ClauseVisitor().visit(parsed)