let prelude = import! std.prelude
let { (<|) } = import! std.function
let { run, Test, assert_eq, test, group, ? } = import! std.test
let { (*>), ? } = import! std.applicative

let { ? } = import! std.effect

let ints input =
    match input with
    | 0 -> 1
    | 1 -> 2
    | _ -> 3

let strings input =
    match input with
    | "A" -> 4
    | "B" -> 5
    | _ -> 6

type N = | A Int | B

let ns input =
    match input with
    | A 1 -> 7
    | A 2 -> 8
    | B -> 9
    | _ -> 10

type R1 = { x: Int }

let r1 input =
    match input with
    | { x = 2 } -> 11
    | { x = 3 } -> 12
    | _ -> 13

type R2 = { x: Int, y: Int }

let r2 input =
    match input with
    | { x = 2, y = 3 } -> 14
    | { x = 3, y = 4 } -> 15
    | _ -> 16

type TestM = | TestM Int String

let test_m input =
    match input with
    | TestM 1 "hello" -> 20
    | TestM _ "world" -> 21
    | TestM 2 _ -> 22
    | _ -> 23

let match_ns =
    assert_eq (ns (A 1)) 7
        *> assert_eq (ns (A 2)) 8
        *> assert_eq (ns B) 9
        *> assert_eq (ns (A 3)) 10

let match_ints =
    assert_eq (ints 0) 1
        *> assert_eq (ints 1) 2
        *> assert_eq (ints 2) 3
        *> assert_eq (ints 3) 3

let match_strings =
    assert_eq (strings "A") 4
        *> assert_eq (strings "B") 5
        *> assert_eq (strings "") 6

let match_r1 =
    assert_eq (r1 { x = 2 }) 11
        *> assert_eq (r1 { x = 3 }) 12
        *> assert_eq (r1 { x = 4 }) 13

let match_r2 =
    assert_eq (r2 { x = 2, y = 3 }) 14
        *> assert_eq (r2 { x = 3, y = 4 }) 15
        *> assert_eq (r2 { x = 4, y = 4 }) 16

let match_test_m =
    assert_eq (test_m (TestM 1 "hello")) 20
        *> assert_eq (test_m (TestM 2 "world")) 21
        *> assert_eq (test_m (TestM 2 "hello")) 22
        *> assert_eq (test_m (TestM 3 "")) 23

group "match_literal" [test "match_ints" <| \_ -> match_ints, test "match_strings" <| \_ -> match_strings, test "match_ns" <| \_ -> match_ns, test "match_r1" <| \_ -> match_r1, test "match_r2" <| \_ -> match_r2, test "match_test_m" <| \_ -> match_test_m]