def assert_true(query, e=None):
if e is None:
e = Engine()
terms, vars = e.parse(query)
term, = terms
e.run_query_in_current(term)
return dict([(name, var.dereference(None))
for name, var in vars.iteritems()])
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_library_dir_single_query():
e = Engine()
tempdir = "__temp__"
create_dir(tempdir)
try:
assert_true("add_library_dir('%s')." % tempdir, e)
assert_true("library_directory('%s')." % tempdir, e)
finally:
delete_dir(tempdir)
def test_asserta_other_module():
e = Engine()
assert_true("asserta(m:f(a)).", e)
assert len(e.modulewrapper.modules) == 2
assert_true("m:f(a).", e)
prolog_raises("existence_error(_, _)", "f(a)", e)
assert_true("module(m).", e)
assert_true("f(a).", e)
assert_true("module(user).", e)
prolog_raises("existence_error(_, _)", "f(a)", e)
def test_importlist_with_not_existing_rule():
e = Engine()
m = "mod"
create_file(m, """
:- module('%s', [f/1]).
""" % m)
try:
prolog_raises("import_error(mod, 'f/1')", "use_module(%s)" % m, e)
assert e.modulewrapper.current_module.name == "user"
finally:
delete_file(m)
def test_load_broken_module_twice():
e = Engine()
m = "mod"
create_file(m, """
:- module(%s, [f/1]).
""" % m)
try:
prolog_raises("import_error(mod, 'f/1')", "use_module('%s')" % m, e)
assert_true("use_module('%s')." % m, e)
assert m in e.modulewrapper.modules
finally:
delete_file(m)
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_engine_current_module_after_invalid_import():
m = "m.pl"
create_file(m, """
:- module(m, [f(a)]).
f(a).
""")
e = Engine()
try:
try: # XXX strange, prolog_raises does not catch the error
prolog_raises("type_error(_, _)", "use_module(m)", e)
except UncaughtError:
pass
assert e.modulewrapper.current_module.name == "user"
finally:
delete_file(m)
def test_add_library_twice():
e = Engine()
lib1 = "__lib1__"
lib2 = "__lib2__"
create_dir(lib1)
create_dir(lib2)
try:
assert_true("add_library_dir('%s')." % lib1, e)
assert len(e.modulewrapper.libs) == 1
assert_true("add_library_dir('%s')." % lib1, e)
assert len(e.modulewrapper.libs) == 1
assert_true("add_library_dir('%s')." % lib2, e)
assert len(e.modulewrapper.libs) == 2
finally:
delete_dir(lib1)
delete_dir(lib2)
def test_module_assert_retract():
e = Engine()
assert_true("module(m).", e)
assert_true("assert(x).", e)
assert_true("asserta(y).", e)
assert_true("x, y.", e)
assert_true("module(user).", e)
assert_false("retract(x).", e)
assert_false("retract(y).", e)
assert_true("assert(x).", e)
assert_true("x.", e)
assert_true("module(m).", e)
assert_true("retract(x).", e)
prolog_raises("existence_error(X, Y)", "x", e)
assert_true("module(user).", e)
assert_true("x.", e)
def test_prefix_module_in_other_directory():
d = "__dir__"
create_dir(d)
m = "mod"
create_file("%s/%s" % (d, m), """
:- module(%s, [f/1]).
f(a).
""" % m)
e = Engine()
try:
assert_true("use_module('%s/%s')." % (d, m), e)
assert_true("current_module(%s)." % m, e)
assert_true("%s:f(X), X == a." % m, e)
finally:
delete_dir(d)
def test_add_library_dir():
e = Engine()
m = e.modulewrapper
assert m.libs == []
prolog_raises("existence_error(X, Y)", "add_library_dir('does_not_exist')",
e)
lib1 = "__lib1__"
lib2 = "__lib2__"
create_dir(lib1)
create_dir(lib2)
try:
assert_true("add_library_dir('%s')." % lib1, e)
assert_true("add_library_dir('%s')." % lib2, e)
assert len(m.libs) == 2
finally:
delete_dir(lib1)
delete_dir(lib2)
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 assert_false(query, e=None):
if e is None:
e = Engine()
term = e.parse(query)[0][0]
py.test.raises(UnificationFailed, e.run_query_in_current, term)
