Algorithms.hs

{-# LANGUAGE ExplicitForAll #-}
{-# LANGUAGE FlexibleContexts #-}
-- |
-- Module      : Data.Massiv.Array.Mutable.Algorithms
-- Copyright   : (c) Alexey Kuleshevich 2019
-- License     : BSD3
-- Maintainer  : Alexey Kuleshevich <lehins@yandex.ru>
-- Stability   : experimental
-- Portability : non-portable
--
module Data.Massiv.Array.Mutable.Algorithms
  ( quicksortM_
  , unstablePartitionM
  ) where

import Data.Massiv.Array.Ops.Sort
import Data.Massiv.Core.Common


-- | Partition elements of the supplied mutable vector according to the predicate.
--
-- ==== __Example__
--
-- >>> import Data.Massiv.Array as A
-- >>> import Data.Massiv.Array.Mutable.Algorithms
-- >>> m <- thaw ([2,1,50,10,20,8] :: Array P Ix1 Int)
-- >>> unstablePartitionM m (<= 10)
-- 4
-- >>> freeze Seq m
-- Array P Seq (Sz1 6)
--   [ 2, 1, 8, 10, 20, 50 ]
--
-- @since 0.3.2
unstablePartitionM ::
     forall r e m. (Mutable r Ix1 e, PrimMonad m)
  => MArray (PrimState m) r Ix1 e
  -> (e -> Bool) -- ^ Predicate
  -> m Ix1
unstablePartitionM marr f = unsafeUnstablePartitionRegionM marr f 0 (unSz (msize marr) - 1)