\begin{code}
-- | 
-- Maintainer : silva.samuel@alumni.uminho.pt
-- Stability  : experimental
-- Portability: portable
-- This module implements specific music notation
module Music.Analysis.Abstract.Notations where
import Music.Analysis.PF ((><), p1)
import Music.Analysis.Base (Number, Text, Invariant(..))
import Music.Analysis.Abstract.Settings (Settings)
import Music.Analysis.Abstract.Motive 
import Music.Analysis.Abstract.Zip as Zip
import Data.Ord (Ord(..))
import Data.Bool (Bool(..))
import Data.Function (id, (.))
import Data.Either (Either(..))
import Data.Maybe (Maybe(..))
import Prelude () 
\end{code}

This are defined settings to Motive NotationNode, that will be equal to Zip
settings.
\begin{code}
-- | Info
type NotationInfo = Either Text Number
-- | New Notation Node
type NotationNode = [(NotationPosition, NotationInfo)]   -- for each note
-- | New Notation Position
type NotationPosition = Maybe Position -- Nothing -> Point; Just -> Interval (more x)
-- | Position
type Position = Number
-- | sefault settings
settings :: Settings
settings = Zip.settings
instance Invariant NotationPosition where
    invariant (Just n) | n < 0 = False
    invariant _ = True
\end{code}

\begin{code}
-- |
addNotation :: NotationPosition -> NotationInfo -> NotationNode -> NotationNode
addNotation a b = (:) (a,b) 
\end{code}

Next functions are combinators like transpose.
\begin{code}
-- | transpose using above layers
transpose :: Number -> Motive (VoiceZipAbsolute, NotationNode) -> 
        Motive (VoiceZipAbsolute, NotationNode)
transpose n = joinMotivePair .
    ((Zip.transpose n) >< id) .
    splitMotivePair
-- | tempo transformation using above layers
tempo :: Number -> Motive (VoiceZipAbsolute, NotationNode) -> 
        Motive (VoiceZipAbsolute, NotationNode)
tempo n = 
    joinMotivePair . ((Zip.tempo n) >< id) . splitMotivePair
-- | duration computation using above layers
duration :: Motive (VoiceZipNode, NotationNode) -> Number
duration = Zip.duration . p1 . splitMotivePair
-- | reverse using above layers
reverse :: Motive (VoiceZipNode, NotationNode) -> 
        Motive (VoiceZipNode, NotationNode)
reverse = 
    joinMotivePair . (Zip.reverse >< id) . splitMotivePair
-- | relative transformation using above layers
relative :: Motive (VoiceZipAbsolute, NotationNode) -> 
        Motive (VoiceZipRelative, NotationNode)
relative = 
    joinMotivePair . (Zip.relative >< id) . splitMotivePair
-- | absolute transformation using above layers
absolute :: Motive (VoiceZipRelative, NotationNode) -> 
        Motive (VoiceZipAbsolute, NotationNode)
absolute = 
    joinMotivePair . (Zip.absolute >< id) . splitMotivePair
\end{code}