f {.x; .y}, [_], (_, _) = x + y

x = f {.x = 1; .y = 2}, [3], (4, 5)
assert x == 3

g _: Int = None
g 10

h _: Int, _: Int = None
h 10, 20

y = match [1, 2]:
    [1, 2, 3] -> 6
    [x, 2] -> x
assert y == 1
a = match { .x = 1 }:
    { y; } -> y + 100
    { x; y } -> 200 + x + y
    { x; } -> x
assert a == 1
b = match { .x = [1, 2]; }:
    { y; } -> y + 100
    { x; y; } -> 200 + x + y
    { x = [1, y]; } -> y
assert b == 2
c = match [[1, 2], [3, 4]]:
    [x, [3, 5]] -> x + 100
    [x, y, z] => 200 + x + y + z
    [[1, x], [3, y]] -> x + y
assert c == 6

#[
and: [Bool; 2] -> Bool
and [True, t] = t
and [_, _] = False
assert and [True, True]
]#