module ADP.Fusion.Term.Strng.Subword where
import Data.Strict.Tuple
import Data.Vector.Fusion.Stream.Size
import Data.Vector.Fusion.Util (delay_inline)
import Debug.Trace
import Prelude hiding (map)
import qualified Data.Vector.Fusion.Stream.Monadic as S
import qualified Data.Vector.Generic as VG
import Data.PrimitiveArray
import ADP.Fusion.Base
import ADP.Fusion.Term.Strng.Type
instance
( Monad m
, Element ls Subword
, MkStream m ls Subword
) => MkStream m (ls :!: Strng v x) Subword where
mkStream (ls :!: Strng slice mn mx v) (IStatic ()) hh (Subword (i:.j))
= S.filter (\s -> let Subword (k:.l) = getIdx s in lk <= mx)
. S.map (\s -> let (Subword (_:.l)) = getIdx s
in ElmStrng (slice l (jl) v) (subword l j) (subword 0 0) s)
$ mkStream ls (IVariable ()) hh (delay_inline Subword (i:.j mn))
mkStream (ls :!: Strng slice mn mx v) (IVariable ()) hh (Subword (i:.j))
= S.flatten mk step Unknown $ mkStream ls (IVariable ()) hh (delay_inline Subword (i:.j mn))
where mk s = let Subword (_:.l) = getIdx s in return (s :. j l mn)
step (s:.z) | z >= 0 = do let Subword (_:.k) = getIdx s
l = j z
kl = subword k l
return $ S.Yield (ElmStrng (slice k (lk) v) kl (subword 0 0) s) (s:.z1)
| otherwise = return $ S.Done