HashMapTests.milone

open Std.StdList
open Std.StdTesting
open Std.Vector
open Std.HashMap
open Std.StdOption

module MB = Std.HashMap.HashMapBuffer

module private Int =
  let equals (l: int) r = l = r
  let hash (value: int) = value

module private String =
  let equals (l: string) r = l = r

  let hash (value: string) =
    let rec go (h: uint) i =
      if i < value.Length then
        let h = h ^^^ ((h <<< 5) ||| (h >>> 27))
        go (h ^^^ (uint (byte value.[i]))) (i + 1)
      else
        h

    int(go 31u 0)

let private debugPair (l: int, r: int) = "(" + string l + ", " + string r + ")"

let private compareInt2 (l: int * int) (r: int * int) = compare (fst l) (fst r)

let private testRemove () =
  let map =
    MB.empty Int.equals (fun (n: int) -> n % 2)
    |> MB.insert 0 100
    |> MB.insert 1 101
    |> MB.insert 2 102
    |> MB.insert 3 103

  let k = 1
  let opt, map = map |> MB.remove k
  // printfn "%d -> %s" k (Option.debug debugPair opt)

  assert (opt
          |> shouldEqual (Option.debug debugPair) (Some(1, 101)))

  let k = 3
  let x, map = map |> MB.tryFind k
  // printfn "%d -> %s" k (Option.debug string x)
  assert (x |> shouldEqual (Option.debug string) (Some 103))

  let k = 4
  let opt, map = map |> MB.remove k
  // printfn "%d -> %s" k (Option.debug debugPair opt)
  assert (opt |> shouldEqual (Option.debug debugPair) None)

  MB.dispose map

let private testOfList () =
  let map =
    MB.ofList String.equals String.hash [ "zero", 0; "one", 1; "two", 2 ]

  let x, map = MB.tryFind "one" map
  assert (x |> shouldEqual (Option.debug string) (Some 1))

  MB.dispose map

let private testToList () =
  let map =
    MB.empty Int.equals Int.hash
    |> MB.insert 0 100
    |> MB.insert 1 101
    |> MB.insert 2 102
    |> MB.insert 3 103

  let entries, map = MB.toList map
  MB.dispose map

  let entries = List.sortWith compareInt2 entries
  assert (shouldEqual (List.debug debugPair) [ 0, 100; 1, 101; 2, 102; 3, 103 ] entries)

let testHashMap () =
  testRemove ()
  testOfList ()
  testToList ()