Update documentation and haddocks for Vect

Author: cloudhead

sdl2.cabal

@@ -72,6 +72,7 @@ library
     SDL.Video.Renderer
 
     SDL.Internal.Types
+    SDL.Internal.Vect
 
     SDL.Raw
     SDL.Raw.Audio
@@ -91,7 +92,6 @@ library
   other-modules:
     Data.Bitmask
     SDL.Internal.Numbered
-    SDL.Internal.Vect
     SDL.Exception
 
   hs-source-dirs:

src/SDL/Internal/Vect.hs

@@ -1,27 +1,47 @@
 {-# LANGUAGE ScopedTypeVariables #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+
+-- 2-D, 3-D and 4-D Vectors.
+-- The interface is compatible with that of the 'linear' package.
 module SDL.Internal.Vect
     ( V2(..)
     , V3(..)
     , V4(..)
     , Point(..)
     ) where
 
--- Copied from the 'linear' package by Edward Kmett.
+-- From the 'linear' package, (c) Edward Kmett.
 
 import           Control.Applicative
 import           Foreign.Storable
 import           Foreign.Ptr (castPtr)
 
+-- | A handy wrapper to help distinguish points from vectors at the
+-- type level.
 newtype Point f a = P (f a)
   deriving (Show, Read, Ord, Eq, Functor, Applicative, Num, Storable)
 
+-- | A 2-dimensional vector
+--
+-- >>> pure 1 :: V2 Int
+-- V2 1 1
+--
+-- >>> V2 1 2 + V2 3 4
+-- V2 4 6
+--
+-- >>> V2 1 2 * V2 3 4
+-- V2 3 8
+--
+-- >>> sum (V2 1 2)
+-- 3
 data V2 a = V2 !a !a
     deriving (Show, Read, Ord, Eq)
 
+-- | A 3-dimensional vector
 data V3 a = V3 !a !a !a
     deriving (Show, Read, Ord, Eq)
 
+-- | A 4-dimensional vector
 data V4 a = V4 !a !a !a !a
     deriving (Show, Read, Ord, Eq)
 

src/SDL/Vect.hs

@@ -1,4 +1,10 @@
 {-# LANGUAGE CPP #-}
+
+-- | SDL's vector representation.
+--
+-- By default, re-exports the vector types from the 'linear' package, but this can be changed via the @-no-linear@
+-- build flag to export SDL's internal vector types from "SDL.Internal.Vect".
+-- This is useful if one does not want to incur the 'lens' dependency.
 module SDL.Vect
   ( module Vect
   ) where