{-# LANGUAGE FlexibleInstances #-}
module HaskellWorks.Data.BalancedParens.BalancedParens
( BalancedParens(..)
, depth
, subtreeSize
) where
import Control.Monad
import Data.Word
import HaskellWorks.Data.BalancedParens.CloseAt
import HaskellWorks.Data.BalancedParens.Enclose
import HaskellWorks.Data.BalancedParens.FindClose
import HaskellWorks.Data.BalancedParens.FindOpen
import HaskellWorks.Data.BalancedParens.OpenAt
import HaskellWorks.Data.Naive
import HaskellWorks.Data.Positioning
import HaskellWorks.Data.RankSelect.Base.Rank0
import HaskellWorks.Data.RankSelect.Base.Rank1
import qualified Data.Vector.Storable as DVS
class (OpenAt v, CloseAt v, FindOpen v, FindClose v, Enclose v) => BalancedParens v where
firstChild :: v -> Count -> Maybe Count
nextSibling :: v -> Count -> Maybe Count
parent :: v -> Count -> Maybe Count
firstChild v p = if openAt v p && openAt v (p + 1) then Just (p + 1) else Nothing
nextSibling v p = if closeAt v p
then Nothing
else openAt v `mfilter` (findClose v p >>= (\q ->
if p /= q
then return (q + 1)
else Nothing))
parent v p = enclose v p >>= (\r -> if r >= 1 then return r else Nothing)
{-# INLINE firstChild #-}
{-# INLINE nextSibling #-}
{-# INLINE parent #-}
depth :: (BalancedParens v, Rank0 v, Rank1 v) => v -> Count -> Maybe Count
depth v p = (\q -> rank1 v q - rank0 v q) <$> findOpen v p
{-# INLINE depth #-}
subtreeSize :: BalancedParens v => v -> Count -> Maybe Count
subtreeSize v p = (\q -> (q - p + 1) `quot` 2) <$> findClose v p
{-# INLINE subtreeSize #-}
instance BalancedParens [Bool]
instance BalancedParens (DVS.Vector Word8)
instance BalancedParens (DVS.Vector Word16)
instance BalancedParens (DVS.Vector Word32)
instance BalancedParens (DVS.Vector Word64)
instance BalancedParens Word8
instance BalancedParens Word16
instance BalancedParens Word32
instance BalancedParens Word64
instance BalancedParens (Naive Word64)