def assert_true(query, e=None):
if e is None:
e = Engine()
terms, vars = e.parse(query)
term, = terms
e.run(term)
return dict([(name, var.dereference(e.heap))
for name, var in vars.iteritems()])
def assert_true(query, e=None):
if e is None:
e = Engine()
terms, vars = e.parse(query)
term, = terms
e.run(term)
return dict([(name, var.dereference(e.heap))
for name, var in vars.iteritems()])
def test_run():
e = Engine()
e.add_rule(Term("f", [Atom.newatom("a"), Atom.newatom("b")]))
X = Var()
Y = Var()
e.add_rule(Term("f", [X, X]))
e.add_rule(Term(":-", [Term("f", [X, Y]),
Term("f", [Y, X])]))
X = e.heap.newvar()
e.run(Term("f", [Atom.newatom("b"), X]))
assert X.dereference(e.heap).name == "b"
e.run(Term("f", [Atom.newatom("b"), Atom.newatom("a")]))
def test_numeral():
from pypy.lang.prolog.interpreter.term import Term, Atom, Var
from pypy.lang.prolog.interpreter.engine import Engine
t = parse_file("""
numeral(null). % end of line comment
numeral(succ(X)) :- numeral(X). % another one
add_numeral(X, null, X).
add_numeral(X, succ(Y), Z) :- add_numeral(succ(X), Y, Z).
greater_than(succ(null), null).
greater_than(succ(X), null) :- greater_than(X, null).
greater_than(succ(X), succ(Y)) :- greater_than(X, Y).
""")
builder = TermBuilder()
facts = builder.build(t)
e = Engine()
for fact in facts:
print fact
e.add_rule(fact)
assert e.signature2function["add_numeral/3"].rulechain.rule.head.args[1].name == "null"
four = Term("succ", [Term("succ", [Term("succ",
[Term("succ", [Atom("null")])])])])
e.run(parse_query_term("numeral(succ(succ(null)))."))
term = parse_query_term(
"""add_numeral(succ(succ(null)), succ(succ(null)), X).""")
e.run(term)
var = Var(0).getvalue(e.heap)
print var, e.heap
# does not raise
var.unify(four, e.heap)
term = parse_query_term(
"""greater_than(succ(succ(succ(null))), succ(succ(null))).""")
e.run(term)
