System.Game.H2048.Core

The core game logic implementation for Game 2048.

The routine for using this library would be:

1. use initGameBoard to get a valid board to begin with. (two new cells are inserted for you, if you want to use an empty board, initBoard is a shorthand)
2. interact with user algorithm etc., use updateBoard to update a board.
3. use insertNewCell to insert a new cell randomly
4. examine if the player wins loses is still alive using gameState.

Documentation

type Board = [[Int]]

represent a 4x4 board for Game 2048 each element should be either zero or 2^i where i >= 1.

type Line = [Int]

a list of 4 elements, stands for one column / row in the board

data Dir

move direction

Constructors

DUp

DDown

DLeft

DRight

Instances

Bounded Dir

Enum Dir

Eq Dir

Ord Dir

Show Dir

data BoardUpdated

result after a successful updateBoard

Constructors

BoardUpdated

Fields

brBoard :: Board

new board

brScore :: Int

score collected in this update

Instances

Eq BoardUpdated

Show BoardUpdated

data GameState

current game state, see also gameState

Constructors

Win

Lose

Alive

Instances

Enum GameState

Eq GameState

Show GameState

gameState :: Board -> GameState

return current game state. Win if any cell is equal to or greater than 2048 or Lose if we can move no further otherwise, Alive.

compactLine :: Line -> Writer (Sum Int) Line

move each non-zero element to their leftmost possible position while preserving the order

initBoard :: Board

the initial board before a game started

initGameBoard :: MonadRandom r => r (Board, Int)

initialize the board by puting two cells randomly into the board. See generateNewCell for the cell generating rule.

updateBoard :: Dir -> Board -> Maybe BoardUpdated

update the board taking a direction, a BoardUpdated is returned on success, if this update does nothing, that means a failure (Nothing)

insertNewCell :: MonadRandom r => Board -> r (Maybe Board)

try to insert a new cell randomly

generateNewCell :: MonadRandom r => r Int

generate a new cell according to the game rule we have 90% probability of getting a cell of value 2, and 10% probability of getting a cell of value 4.