{-# LANGUAGE PatternSynonyms #-}
{-# LANGUAGE CPP #-}
module Data.Wrapper.PSQ
#if 0
     ( module Data.PSQueue ) where ; import Data.PSQueue
#else
    ( module Data.Wrapper.PSQ , module OrdPSQ ) where

import Data.OrdPSQ as OrdPSQ hiding (insert, map, singleton, minView)
import qualified Data.OrdPSQ as OrdPSQ

type PSQ k p = OrdPSQ k p ()
type Binding k p = (k,p,())

pattern (:->) :: k -> p -> Binding k p
pattern k :-> p <- (k,p,()) where k :-> p = (k,p,())

key :: Binding k p -> k
key (k,p,v) = k
{-# INLINE key #-}

prio :: Binding k p -> p
prio (k,p,v) = p
{-# INLINE prio #-}

insert :: (Ord k, Ord p) => k -> p -> PSQ k p -> PSQ k p
insert k p q = OrdPSQ.insert k p () q
{-# INLINE insert #-}

insertWith :: (Ord k, Ord p) => (p -> p -> p) -> k -> p -> PSQ k p -> PSQ k p
insertWith f k p0 q = snd $ OrdPSQ.alter f' k q
 where
    f' (Just (p,())) = ((),Just (f p0 p, ()))
    f' Nothing      = ((),Nothing)
{-# INLINE insertWith #-}

singleton :: (Ord k, Ord p) => k -> p -> PSQ k p
singleton k p = OrdPSQ.singleton k p ()
{-# INLINE singleton #-}

minView :: (Ord k, Ord p) => PSQ k p -> Maybe (Binding k p, PSQ k p)
minView q = fmap (\(k,p,(),q') -> (k :-> p, q')) $ OrdPSQ.minView q
{-# INLINE minView #-}

#endif