{-# LANGUAGE StandaloneDeriving, DeriveDataTypeable, ScopedTypeVariables, ExistentialQuantification, GeneralizedNewtypeDeriving, MultiParamTypeClasses, TemplateHaskell #-} -- Copyright 2008 JP Bernardy -- | Basic types useful everywhere we play with buffers. module Yi.Buffer.Basic where import Prelude (reverse) import Data.Binary import Yi.Prelude import qualified Data.Rope as R import Data.DeriveTH import Data.Ix -- | Direction of movement inside a buffer data Direction = Backward | Forward deriving (Eq,Ord,Typeable,Show,Bounded,Enum) \$(derive makeBinary ''Direction) reverseDir :: Direction -> Direction reverseDir Forward = Backward reverseDir Backward = Forward -- | reverse if Backward mayReverse :: Direction -> [a] -> [a] mayReverse Forward = id mayReverse Backward = reverse -- | 'direction' is in the same style of 'maybe' or 'either' functions, -- It takes one argument per direction (backward, then forward) and a -- direction to select the output. directionElim :: Direction -> a -> a -> a directionElim Backward b _ = b directionElim Forward _ f = f -- | A mark in a buffer newtype Mark = Mark {markId::Int} deriving (Eq, Ord, Show, Typeable, Binary) -- | Reference to a buffer. newtype BufferRef = BufferRef Int deriving (Eq, Ord, Typeable, Binary) deriving instance Num BufferRef instance Show BufferRef where show (BufferRef r) = "B#" ++ show r -- | A point in a buffer newtype Point = Point {fromPoint :: Int} -- offset in the buffer (#codepoints, NOT bytes) deriving (Eq, Ord, Enum, Bounded, Typeable, Binary, Ix) deriving instance Num Point deriving instance Real Point deriving instance Integral Point instance Show Point where show (Point p) = show p -- | Size of a buffer region newtype Size = Size {fromSize :: Int} -- size in bytes (#bytes, NOT codepoints) deriving (Show, Eq, Ord, Num, Enum, Real, Integral, Binary) instance SemiNum Point Size where Point p +~ Size s = Point (p + s) Point p -~ Size s = Point (p - s) Point p ~- Point q = Size (abs (p - q)) fromString :: String -> Rope fromString = R.fromString -- | Window references newtype WindowRef = WindowRef { unWindowRef :: Int } deriving(Eq, Ord, Enum, Show, Typeable, Binary) instance Initializable WindowRef where initial = WindowRef (-1)