temporal-music-notation-0.1.2: src/Temporal/Music/Notation/Seg.hs

module Temporal.Music.Notation.Seg(
       Seg(..), segSize
       -- IntSeg(..),
       -- module TypeLevel.Nat.Decimal
    )
where

--import TypeLevel.Nat.Decimal

-- | 'Seg' means segment, values that 'Enum' and 'Bounded'. 
class (Enum a, Bounded a) => Seg a where
    
segSize :: Seg a => a -> Int
segSize x = 1 + phi maxBound x - phi minBound x
    where phi a b = fromEnum $ a `asTypeOf` b

{-
-- | Bounded 'Int'.  Type parameter encodes 'maxBound',
-- 'minBound' equals to zero.
newtype Nat n => IntSeg n = IntSeg { runIntSeg :: Int }
    deriving (Show, Eq)


instance Nat n => Bounded (IntSeg n) where
    minBound = IntSeg 0
    maxBound = res
        where res = IntSeg $ toInt $ phi res
              phi :: IntSeg n -> n
              phi = const undefined  


instance Nat n => Enum (IntSeg n) where
    fromEnum = runIntSeg
    toEnum x = res
        where res = phi res x
              phi t x 
                | x < a || x > b = error "IntSeg :: out of bounds"
                | otherwise      = IntSeg x
                 where a = fromEnum $ minBound `asTypeOf` t
                       b = fromEnum $ maxBound `asTypeOf` t  

instance Nat n => Seg (IntSeg n)
-}