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|
{-# language BangPatterns #-}
{-# language ViewPatterns #-}
module KWay.PrioMergeAlg
( merge
, mkStreams
) where
import qualified Data.PQueue.Prio.Min as P
import System.Random (StdGen)
import Data.Word
import Data.List (unfoldr)
import KWay.RandomIncreasing
type PQ = P.MinPQueue
merge :: [Stream] -> [Word64]
merge = unfoldr go . P.fromList . map viewStream
where
go :: PQ Word64 Stream -> Maybe (Word64, PQ Word64 Stream)
go (P.minViewWithKey -> Just ((a, viewStream -> (b, s)), ss))
= Just (a, P.insert b s ss)
go _ = Nothing
|
