def test__eq__():
assert Variable("A") == Variable("A")
assert Variable("A") != Variable("B")
with pytest.raises(TypeError) as error:
Variable("A") == "A"
assert str(error.value) == "A must be a Variable"
def test_02():
"""
P02 (*): Find the last but one element of a list
last_but_one(X,L) :- X is the last but one element of the list L
(element,list) (?,?)
last_but_one(X,[X,_]).
last_but_one(X,[_,Y|Ys]) :- last_but_one(X,[Y|Ys]).
"""
Ys = Variable("Ys")
db = [
dict(last_but_one=X, list=(X, _W)),
Rule(
dict(last_but_one=X, list=(_W, Y, *Ys)),
dict(last_but_one=X, list=(Y, *Ys)),
),
]
query = dict(last_but_one=Q, list=["a", "b", "c"])
assert next(search(db, query)) == {Q: "b"}
def test__init__error():
with pytest.raises(ValueError) as error:
Variable(1)
assert str(error.value) == "name must be a string"
def test_new_frame():
assert Variable("A", 3).new_frame(4) == Variable("A", 4)
def test__repr__(name, frame, message):
assert repr(Variable(name, frame)) == message
def test_factory():
assert Variable.factory("A", "B") == [Variable("A"), Variable("B")]
import pytest
from inference_logic import Rule, Variable
from inference_logic.algorithms import search
from inference_logic.data_structures import Assert, Assign, PrologList
X, Y, Z = Variable.factory("X", "Y", "Z")
L, _W = Variable.factory("L", "W")
Q = Variable("Q")
def test_01():
"""
P01 (*): Find the last element of a list
my_last(X,L) :- X is the last element of the list L
(element,list) (?,?)
Note: last(?Elem, ?List) is predefined
my_last(X,[X]).
my_last(X,[_|L]) :- my_last(X,L).
"""
db = [
dict(last=X, list=[X]),
Rule(dict(last=X, list=[_W, *L]), dict(last=X, list=L)),
]
query = dict(last=Q, list=["a", "b", "c"])
assert list(search(db, query)) == [{Q: "c"}]
import pytest
from inference_logic import Rule, Variable
from inference_logic.data_structures import construct, new_frame
A, B = Variable.factory("A", "B")
A_1 = Variable("A", 1)
B_1 = Variable("B", 1)
@pytest.mark.parametrize(
"initial, final",
[
(True, True),
(A, Variable("A", 1)),
((A, True), (A_1, True)),
(dict(a=A), dict(a=A_1)),
],
)
def test_new_frame_function(initial, final):
assert new_frame(construct(initial), 1) == construct(final)
@pytest.mark.parametrize(
"initial, final",
[(Rule(dict(a=A), dict(b=B)), Rule(dict(a=A_1), dict(b=B_1)))],
)
def test_new_frame_method(initial, final):
assert construct(initial).new_frame(1) == construct(final)