First commit, some basic Tetris types

src/Tetris.hs

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+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE RecordWildCards #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE FlexibleInstances #-}
+module Tetris
+    (
+    ) where
+
+import qualified Data.Map as M
+import Lens.Micro
+import Lens.Micro.TH
+import Prelude hiding (Left, Right)
+
+-- | Tetris shape types
+data Tetrimino =
+    I
+  | O
+  | T
+  | S
+  | Z
+  | J
+  | L
+  deriving (Eq, Show, Enum)
+
+-- | Coordinates
+type Coord = (Int, Int)
+type CoordMap = (Int -> Int, Int -> Int)
+
+-- | Tetris shape in coordinate context
+data Block = Block
+  { _shape  :: Tetrimino -- ^ block type
+  , _origin :: Coord -- ^ origin (absolute)
+  , _extra  :: [Coord] -- ^ extraneous cells (relative)
+  } deriving (Eq, Show)
+
+makeLenses ''Block
+
+data Direction = Left | Right | Down
+  deriving (Eq, Show)
+
+-- | Cell state within a tetris board
+data Cell = Filled Tetrimino | Empty
+  deriving (Eq, Show)
+
+-- | Board of cells
+type Board = M.Map Coord Cell
+
+-- | Game state
+data Game = Game
+  { _speed :: Int
+  , _currBlock :: Block
+  , _nextShape :: Tetrimino
+  , _score :: Int
+  , _board :: Board
+  } deriving (Eq, Show)
+
+
+-- Translate class for direct translations, without concern for boundaries
+-- Shiftable concerns safe translations with boundaries
+class Translatable s where
+  translate :: Direction -> s -> s
+
+instance Translatable Coord where
+  translate Left (x, y) = (x-1, y)
+  translate Right (x, y) = (x+1, y)
+  translate Down (x,y) = (x, y-1)
+
+instance Translatable Block where
+  translate d b = b & origin %~ translate d
+
+initI, initO, initS, initZ, initL, initJ, initT :: Block
+initI = Block I (0,0) [(-2,0), (-1,0), (1,0)]
+initO = Block O (0,0) [(-1,0), (-1,-1), (0,-1)]
+initS = Block S (0,0) [(-1,-1), (0,-1), (1,0)]
+initZ = Block Z (0,0) [(-1,0), (0,-1), (1,-1)]
+initL = Block L (0,0) [(-1,-1), (-1,0), (1,0)]
+initJ = Block J (0,0) [(-1,0), (1,0), (1,-1)]
+initT = Block T (0,0) [(-1,0), (0,-1), (1,0)]
+
+-- | Rotate block counter clockwise about origin
+-- *Note*: Strict unsafe rotation not respecting boundaries
+-- Safety can only be assured within Game context
+rotate' :: Block -> Block
+rotate' = (& extra %~ fmap (\(x,y) -> (-y, x)))
+
+-- | Get absolute coordinates of extraneous block cells
+absExtra :: Block -> [Coord]
+absExtra (Block _ (xo,yo) cs) = fmap (\(x,y) -> (x+xo, y+yo)) cs
+
+-- | Get absolute coordinates of all block cells
+absAll :: Block -> [Coord]
+absAll (Block _ o@(xo,yo) cs) = o : fmap (\(x,y) -> (x+xo, y+yo)) cs