The program uses some custom type synonyms.
type Game = (State, Moves)
type State = (Cards, Pieces, Pieces)
type Pieces = [Piece]
type Moves = [Move]
type Move = (Position, Position, Card)
type Piece = (Int, Int)
type Position = (Int, Int)
type PlayerOneTurn = Bool
type Card = String
type Cards = [Card]The generateRandom function works by shuffling a new deck of 5 cards.
It then starts making random moves.
First it shuffles the two cards the player has and all of the players pieces.
It will try the first card on the first piece.
The card's moves will be shuffled an tried in random order.
If no moves are valid, it will try the next card with the same piece.
When all cards and moves have been tried, it will try again with the next piece.
When no pieces are left, it will stop generating the game and return where it got to.
Every time a moves has been made, a new random generator will be used. The code for that is not that pretty
makeRandomMove (snd (random rGen :: (Int, StdGen))) s n gsIt uses the number representation of the earlier generator, and then it generates a random number, but that number is not used, only the generator that comes with it.
First a game is being parsed using the given file. The string input will be turned into a Game, where the first line of a file is the State and the rest of the lines are a list of moves to be made, Moves.
It will start playing the game, by taking the first move in the list and try it. If there are no moves, it results in a ParsingError.
When a move is being made, it will give back the new state of the board. A move can thus give a Maybe State. It returns Nothing if an invalid move was made. The program uses Either to determine if the move was a winning move or just a normal move. Left is a normal move, and Right is a winning move. This way it can check if there are more moves after a winning move.
When a game ends it will return the current state of the board as a string.
Before each move is made, they are being run through a validMove function that look like this.
validMove :: Cards -> Move -> Pieces -> Bool
validMove cs m@(start, end, card) ps = isPlayerCard cs card && isCardMove m && isWithinBoard end && takeOwnPiece m ps && isPlayerPiece start psAfter each move, the program checks if some of the pieces in player B are overlapping with player A, if so remove from player B's pieces. The pieces will be mirrored and switched, and the cards will be switched around as well.