def test_list_applicative_binary_func(self):
f = lambda x, y: x + y
v = List.from_iterable([1, 2])
w = List.from_iterable([4, 8])
self.assertEquals(
pure(f).apply(v).apply(w), List.from_iterable([5, 9, 6, 10]))
def test_list_functor_map(self):
# fmap f (return v) = return (f v)
x = unit(42)
f = lambda x: x * 10
self.assertEqual(x.map(f), unit(420))
y = List.from_iterable([1, 2, 3, 4])
g = lambda x: x * 10
self.assertEqual(y.map(g), List.from_iterable([10, 20, 30, 40]))
def test_do_list_basic(self):
l = lambda *items: List.from_iterable(items)
out1 = do(let(a=l(3, 10, 6)), let(b=l(100, 200)),
lambda e: List.unit(e.a + e.b))
out2 = l(3, 10, 6) | (lambda a: l(100, 200) |
(lambda b: List.unit(a + b)))
self.assertEqual(out1, out2)
def test_do_scoping_correct(self):
try:
l = lambda *items: List.from_iterable(items)
do(let(a=l(1, 2, 3)), let(b=lambda e: List.unit(e.a)),
lambda e: List.unit(e.a * e.b))
except AttributeError:
assert False
def test_list_monad_law_associativity_range(self):
# (m >>= f) >>= g is just like doing m >>= (\x -> f x >>= g)
f = lambda x: unit(x + 1000)
g = lambda y: unit(y * 42)
# Long list
m = List.from_iterable(range(42))
self.assertEqual(m.bind(f).bind(g), m.bind(lambda x: f(x).bind(g)))
def test_identity_applicative_law_composition_range(self):
# pure (.) <*> u <*> v <*> w = u <*> (v <*> w)
u = pure(lambda x: x * 42)
v = pure(lambda x: x + 42)
# Long list
w = List.from_iterable(range(42))
self.assertEquals(
pure(fmap).apply(u).apply(v).apply(w), u.apply(v.apply(w)))
def test_do_list_pythag(self):
r = lambda low, high: List.from_iterable(range(low, high))
out1 = do(let(z=r(1, 21)), let(x=lambda e: r(1, e.z + 1)),
let(y=lambda e: r(e.x, e.z + 1)),
lambda e: guard(List, e.x * e.x + e.y * e.y == e.z * e.z),
lambda e: List.unit((e.x, e.y, e.z)))
out2 = r(1, 21) | (
lambda z: r(1, z + 1) |
(lambda x: r(x, z + 1) |
(lambda y: guard(List, x * x + y * y == z * z) >> List.unit(
(x, y, z)))))
self.assertEqual(out1, out2)
def test_list_functor_law_1(self):
# fmap id = id
# Singleton list using return
x = unit(42)
self.assertEqual(x.map(identity), x)
# Empty list
y = List()
self.assertEqual(y.map(identity), y)
# Long list
z = List.from_iterable(range(42))
self.assertEqual(z.map(identity), z)
def test_list_applicative_law_identity(self):
# pure id <*> v = v
# Singleton list
x = unit(42)
self.assertEquals(pure(identity).apply(x), x)
# Empty list
y = List.empty()
self.assertEquals(pure(identity).apply(y), y)
# Log list
y = List.from_iterable(range(42))
self.assertEquals(pure(identity).apply(y), y)
def test_list_applicative_law_functor(self):
# pure f <*> x = fmap f x
f = lambda x: x * 42
x = unit(42)
self.assertEquals(pure(f).apply(x), x.map(f))
# Empty list
z = List()
self.assertEquals(pure(f).apply(z), z.map(f))
# Long list
z = List.from_iterable(range(42))
self.assertEquals(pure(f).apply(z), z.map(f))
def _get_setup_args(path):
rtn = List.empty()
with open(path, 'rU') as file:
t = compile(file.read(), path, 'exec', ast.PyCF_ONLY_AST)
for node in (n for n in t.body if isinstance(n, ast.Expr)):
if isinstance(node.value, ast.Call):
if hasattr(node.value.func,
'id') and node.value.func.id == 'setup':
rtn = List.from_iterable(node.value.keywords)
break
else:
print(dir(node.value.func), node.value.func.value)
return rtn
def test_list_functor_law2(self):
# fmap (f . g) x = fmap f (fmap g x)
def f(x):
return x + 10
def g(x):
return x * 10
# Singleton list
x = unit(42)
self.assertEquals(x.map(compose(f, g)), x.map(g).map(f))
# Empty list
y = List.empty()
self.assertEquals(y.map(compose(f, g)), y.map(g).map(f))
# Long list
z = List.from_iterable(range(42))
self.assertEquals(z.map(compose(f, g)), z.map(g).map(f))
def test_list_append_non_empty(self):
xs = List.from_iterable(range(5))
ys = List.from_iterable(range(5, 10))
zs = xs.append(ys)
self.assertEqual(List.from_iterable(range(10)), zs)
def test_list_length_multiple(self):
xs = List.from_iterable(range(42))
self.assertEqual(42, len(xs))
def test_list_applicative_empty_func(self):
v = unit(42)
w = List.from_iterable([1, 2, 3])
self.assertEquals(List.empty().apply(v).apply(w), List(Unit))
