def test_queryNonRecursiveIDBPredicate():
db = facts([p("a", "b"), p("b", "c"), p("c", "d")])
rules = [q(X, Y) <= [p(X, Z), p(Z, Y)]]
ans = match3(db, rules)
ans(q(X, Y), [(a, c), (b, d)])
ans(q(X, c), [(a, )])
ans(q("x", b), [])
def test_queryEDBPredicate():
a_q1 = q("a", "b", "c", "d", "e")
a_q2 = q("e", "d", "c", "b", "a")
db = [p(), a_q1, a_q2]
assert match_relations(db, p(), [p()])
ans = match3(facts(db), [])
ans(q(V, W, X, Y, Z), [(a, b, c, d, e), (e, d, c, b, a)])
ans(q(W, "b", X, Y, Z), [(a, c, d, e)])
ans(q(W, X, "d", Y, Z), [])
def test_queryNonLinearlyRecursiveIDBPredicate():
db = facts([
p("a", "b"),
p("b", "c"),
p("c", "d"),
])
rules = [
q(X, Y) <= p(X, Y),
q(X, Y) <= [q(X, Z), q(Z, Y)],
]
ans = match3(db, rules)
ans(q(X, Y), [(a, b), (a, c), (a, d), (b, c), (b, d), (c, d)])
ans(q(a, X), [(b, ), (c, ), (d, )])
def test_queryLinearlyRecursiveIDBPredicate():
# // Acyclic transitive closure.
db = facts([
p("a", "b"),
p("b", "c"),
p("c", "d"),
])
rules = [
q(X, Y) <= p(X, Y),
q(X, Y) <= [p(X, Z), q(Z, Y)],
]
ans = match3(db, rules)
ans(q(X, Y), [(a, b), (a, c), (a, d), (b, c), (b, d), (c, d)])
ans(q("a", X), [(b, ), (c, ), (d, )])
def test_transitive_closure_with_a_cycle():
# // Transitive closure with a cycle.
db = facts([
p("a", "b"),
p("b", "c"),
p("c", "d"),
p("d", "c"),
])
rules = [q(X, Y) <= p(X, Y), q(X, Y) <= [p(X, Z), q(Z, Y)]]
ans = match3(db, rules)
ans(
q(X, Y),
[(a, b), (a, c), (a, d), (b, c), (b, d), (c, c), (c, d), (d, c),
(d, d)],
)
def test_queryNonLinearlyRecursiveIDBPredicate_withCycle():
# // Transitive closure with a cycle.
db = facts([
p("a", "b"),
p("b", "c"),
p("c", "d"),
p("d", "c"),
])
rules = [
q(X, Y) <= p(X, Y),
q(X, Y) <= [q(X, Z), q(Z, Y)],
]
ans = match3(db, rules)
ans(
q(X, Y),
[(a, b), (a, c), (a, d), (b, c), (b, d), (c, c), (c, d), (d, c),
(d, d)],
)
def test_queryUndefinedPredicate():
db1 = facts([p()])
match3(db1, [], q(), [])
def test_queryIDBPredicateWithExplicitIDBFact():
# // Note that q is defined by a rule, but we also give an explicit fact.
db = facts([r("a", "b"), q("b", "c")])
rules = [q(X, Y) <= r(X, Y)]
ans = match3(db, rules)
ans(q(X, Y), [(a, b), (b, c)])
def test_queryIDBPredicateWithUndefinedEDB():
db = facts([r("a", "b")])
rules = [q(X, Y) <= p(X, Y)]
ans = match3(db, rules)
ans(q(X, Y), [])