{-|
Module : FPPrac.Graphics.NormalizeNumber
Description : Used in the FPPrac module to normalize any instance of a Num type to float.
It is used for the "EventLoop" module.
Copyright : (c) Sebastiaan la Fleur, 2014
License : BSD3
Maintainer : sebastiaan.la.fleur@gmail.com
Stability : experimental
Portability : All
In the "EventLoop" module, 'Float's are used to express positions and other characteristics. As that package is also used
in the functional programming lab at the University of Twente, compatibility with the "FPPrac" module is needed.
That module expresses a 'Number' type which abstracts from 'Int' and 'Double' types. This module is used to normalize
both the 'Number' type and the original 'Num' class instances defined in Haskell.
-}
module FPPrac.Graphics.NormalizeNumber where
import GHC.Float
import FPPrac.Prelude.Number
{-|
Class to express that the instance 'a' is able to be normalized to a 'Float'.
-}
class (Num a) => NormalizeNumber a where
-- | The function that can be used to normalize 'a' to a 'Float'.
normalize :: a -> Float
{-# MINIMAL normalize #-}
-- | How to normalize a 'Float'
instance NormalizeNumber Float where
normalize f = f
-- | How to normalize an 'Int'
instance NormalizeNumber Int where
normalize = fromIntegral
-- | How to normalize an 'Integer'
instance NormalizeNumber Integer where
normalize = fromIntegral
-- | How to normalize a 'Double'
instance NormalizeNumber Double where
normalize = double2Float
-- | How to normalize a 'Number'. This is definied in "FPPrac.Prelude.Number" in the twentefp-number package
instance NormalizeNumber Number where
normalize (I i) = fromIntegral i
normalize (F d) = double2Float d