miniMax Algorithm in Elm - Tests - next move wins - Implementation 3 - Fold using List.all instead

Scorer.elm

module Scorer exposing (..)

import Array exposing (fromList, get, map, set, toList)
import List exposing (all, foldl, map)
import Maybe exposing (withDefault)


markerX : Char
markerX =
    'X'


empty : Char
empty =
    ' '


nextBestMove : List (List Char) -> Int
nextBestMove gameNode =
    let
        node =
            List.map fromList gameNode

        gameNodeAsArray =
            fromList node

        row1 =
            get 0 gameNodeAsArray

        row1NextState =
            set 2 markerX (withDefault (Array.initialize 3 (always empty)) row1)

        row2 =
            get 1 gameNodeAsArray

        row2NextState =
            set 2 markerX (withDefault (Array.initialize 3 (always empty)) row2)
    in
    if winnerFound markerX row1NextState then
        2
    else if winnerFound markerX row2NextState then
        5
    else
        0


winnerFound : Char -> Array.Array Char -> Bool
winnerFound marker row =
    let
        rowAsList =
            toList row
    in
    all (\cell -> cell == marker) rowAsList