def test_numeral():
from prolog.interpreter.term import Callable, Atom, BindingVar
from prolog.interpreter.continuation 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()
m = e.modulewrapper
for fact in facts:
print fact
e.add_rule(fact)
assert m.modules["user"].lookup(Signature.getsignature("add_numeral", 3)).rulechain.head.argument_at(1).name() == "null"
four = Callable.build("succ", [Callable.build("succ", [Callable.build("succ",
[Callable.build("succ", [Callable.build("null")])])])])
e.run_query_in_current(parse_query_term("numeral(succ(succ(null)))."))
term = parse_query_term(
"""add_numeral(succ(succ(null)), succ(succ(null)), X).""")
e.run_query_in_current(term)
hp = Heap()
var = BindingVar().dereference(hp)
# does not raise
var.unify(four, hp)
term = parse_query_term(
"""greater_than(succ(succ(succ(null))), succ(succ(null))).""")
e.run_query_in_current(term)
def test_numeral():
from prolog.interpreter.term import Callable, Atom, BindingVar
from prolog.interpreter.continuation 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()
m = e.modulewrapper
for fact in facts:
print fact
e.add_rule(fact)
assert m.modules["user"].lookup(Signature.getsignature(
"add_numeral", 3)).rulechain.head.argument_at(1).name() == "null"
four = Callable.build("succ", [
Callable.build("succ", [
Callable.build("succ",
[Callable.build("succ", [Callable.build("null")])])
])
])
e.run_query_in_current(parse_query_term("numeral(succ(succ(null)))."))
term = parse_query_term(
"""add_numeral(succ(succ(null)), succ(succ(null)), X).""")
e.run_query_in_current(term)
hp = Heap()
var = BindingVar().dereference(hp)
# does not raise
var.unify(four, hp)
term = parse_query_term(
"""greater_than(succ(succ(succ(null))), succ(succ(null))).""")
e.run_query_in_current(term)
def test_run():
e = Engine()
e.add_rule(Callable.build("f", [Callable.build("a"), Callable.build("b")]))
X = BindingVar()
Y = BindingVar()
c = Callable.build("f", [X, X])
e.add_rule(c)
c2 = Callable.build(":-", [Callable.build("f", [X, Y]),
Callable.build("f", [Y, X])])
e.add_rule(c2)
hp = Heap()
X = hp.newvar()
c3 = Callable.build("f", [Callable.build("b"), X])
e.run_query_in_current(c3)
assert X.dereference(hp).name()== "b"
query = Callable.build("f", [Callable.build("b"), Callable.build("a")])
e.run_query_in_current(query)
def test_run():
e = Engine()
e.add_rule(Callable.build("f", [Callable.build("a"), Callable.build("b")]))
X = BindingVar()
Y = BindingVar()
c = Callable.build("f", [X, X])
e.add_rule(c)
c2 = Callable.build(
":-", [Callable.build("f", [X, Y]),
Callable.build("f", [Y, X])])
e.add_rule(c2)
hp = Heap()
X = hp.newvar()
c3 = Callable.build("f", [Callable.build("b"), X])
e.run_query_in_current(c3)
assert X.dereference(hp).name() == "b"
query = Callable.build("f", [Callable.build("b"), Callable.build("a")])
e.run_query_in_current(query)