From 885a66f45a8d76a8a8e95a0347a176cce1d5732b Mon Sep 17 00:00:00 2001
From: Harendra Kumar <harendra.kumar@gmail.com>
Date: Sun, 22 Sep 2019 22:07:58 +0530
Subject: [PATCH] merge Streamly.Fold.Internal with Streamly.Internal.Data.Fold

---
 src/Streamly/Data/Fold.hs          |  1 -
 src/Streamly/Fold/Internal.hs      | 66 ------------------------------
 src/Streamly/Internal.hs           |  2 +-
 src/Streamly/Internal/Data/Fold.hs | 43 +++++++++++++++++++
 streamly.cabal                     |  1 -
 5 files changed, 44 insertions(+), 69 deletions(-)
 delete mode 100644 src/Streamly/Fold/Internal.hs

diff --git a/src/Streamly/Data/Fold.hs b/src/Streamly/Data/Fold.hs
index 330a4209f..62cac778d 100644
--- a/src/Streamly/Data/Fold.hs
+++ b/src/Streamly/Data/Fold.hs
@@ -244,4 +244,3 @@ import Prelude
                span, splitAt, break, mapM)
 
 import Streamly.Internal.Data.Fold
-import Streamly.Internal.Data.Fold.Types
diff --git a/src/Streamly/Fold/Internal.hs b/src/Streamly/Fold/Internal.hs
deleted file mode 100644
index d500080f5..000000000
--- a/src/Streamly/Fold/Internal.hs
+++ /dev/null
@@ -1,66 +0,0 @@
-{-# LANGUAGE BangPatterns              #-}
-{-# LANGUAGE CPP                       #-}
-{-# LANGUAGE ExistentialQuantification #-}
-{-# LANGUAGE FlexibleContexts          #-}
-{-# LANGUAGE RankNTypes #-}
-{-# LANGUAGE RecordWildCards #-}
-{-# LANGUAGE ScopedTypeVariables #-}
-
--- |
--- Module      : Streamly.Fold.Internal
--- Copyright   : (c) 2019 Composewell Technologies
---               (c) 2013 Gabriel Gonzalez
--- License     : BSD3
--- Maintainer  : harendra.kumar@gmail.com
--- Stability   : experimental
--- Portability : GHC
-
-module Streamly.Fold.Internal
-    (
-      rollingHash
-    , rollingHashWithSalt
-    -- , rollingHashFirstN
-    -- , rollingHashLastN
-    )
-where
-
-import Streamly.Internal.Data.Fold.Types (Fold(..))
-
--- | Compute an 'Int' sized polynomial rolling hash
---
--- > H = salt * k ^ n + c1 * k ^ (n - 1) + c2 * k ^ (n - 2) + ... + cn * k ^ 0
---
--- Where @c1@, @c2@, @cn@ are the elements in the input stream and @k@ is a
--- constant.
---
--- This hash is often used in Rabin-Karp string search algorithm.
---
--- See https://en.wikipedia.org/wiki/Rolling_hash
---
--- @since 0.7.0
-{-# INLINABLE rollingHashWithSalt #-}
-rollingHashWithSalt :: (Monad m, Enum a) => Int -> Fold m a Int
-rollingHashWithSalt salt = Fold step initial extract
-    where
-    k = 2891336453
-    initial = return salt
-    step cksum a = return $ cksum * k + fromEnum a
-    extract = return
-
--- | A default salt used in the implementation of 'rollingHash'.
-{-# INLINE defaultSalt #-}
-defaultSalt :: Int
-#if WORD_SIZE_IN_BITS == 64
-defaultSalt = 0xdc36d1615b7400a4
-#else
-defaultSalt = 0x087fc72c
-#endif
-
--- | Compute an 'Int' sized polynomial rolling hash of a stream.
---
--- > rollingHash = rollingHashWithSalt defaultSalt
---
--- @since 0.7.0
-{-# INLINABLE rollingHash #-}
-rollingHash :: (Monad m, Enum a) => Fold m a Int
-rollingHash = rollingHashWithSalt defaultSalt
diff --git a/src/Streamly/Internal.hs b/src/Streamly/Internal.hs
index ed34f1ac5..181d4d50e 100644
--- a/src/Streamly/Internal.hs
+++ b/src/Streamly/Internal.hs
@@ -55,5 +55,5 @@ import Streamly.Streams.Combinators (inspectMode)
 import Streamly.Unfold.Types (Unfold(..))
 import Streamly.Unfold (fromList)
 
-import Streamly.Fold.Internal
+import Streamly.Internal.Data.Fold
 import Streamly.Internal.Data.Fold.Types
diff --git a/src/Streamly/Internal/Data/Fold.hs b/src/Streamly/Internal/Data/Fold.hs
index 294b3e579..65de1c768 100644
--- a/src/Streamly/Internal/Data/Fold.hs
+++ b/src/Streamly/Internal/Data/Fold.hs
@@ -50,6 +50,10 @@ module Streamly.Internal.Data.Fold
     , mean
     , variance
     , stdDev
+    , rollingHash
+    , rollingHashWithSalt
+    -- , rollingHashFirstN
+    -- , rollingHashLastN
 
     -- ** Full Folds (Monoidal)
     , mconcat
@@ -486,6 +490,45 @@ variance = Fold step (return begin) (return . done)
 stdDev :: (Monad m, Floating a) => Fold m a a
 stdDev = sqrt variance
 
+-- | Compute an 'Int' sized polynomial rolling hash
+--
+-- > H = salt * k ^ n + c1 * k ^ (n - 1) + c2 * k ^ (n - 2) + ... + cn * k ^ 0
+--
+-- Where @c1@, @c2@, @cn@ are the elements in the input stream and @k@ is a
+-- constant.
+--
+-- This hash is often used in Rabin-Karp string search algorithm.
+--
+-- See https://en.wikipedia.org/wiki/Rolling_hash
+--
+-- @since 0.7.0
+{-# INLINABLE rollingHashWithSalt #-}
+rollingHashWithSalt :: (Monad m, Enum a) => Int -> Fold m a Int
+rollingHashWithSalt salt = Fold step initial extract
+    where
+    k = 2891336453
+    initial = return salt
+    step cksum a = return $ cksum * k + fromEnum a
+    extract = return
+
+-- | A default salt used in the implementation of 'rollingHash'.
+{-# INLINE defaultSalt #-}
+defaultSalt :: Int
+#if WORD_SIZE_IN_BITS == 64
+defaultSalt = 0xdc36d1615b7400a4
+#else
+defaultSalt = 0x087fc72c
+#endif
+
+-- | Compute an 'Int' sized polynomial rolling hash of a stream.
+--
+-- > rollingHash = rollingHashWithSalt defaultSalt
+--
+-- @since 0.7.0
+{-# INLINABLE rollingHash #-}
+rollingHash :: (Monad m, Enum a) => Fold m a Int
+rollingHash = rollingHashWithSalt defaultSalt
+
 ------------------------------------------------------------------------------
 -- Monoidal left folds
 ------------------------------------------------------------------------------
diff --git a/streamly.cabal b/streamly.cabal
index c579e2985..eb9d1fded 100644
--- a/streamly.cabal
+++ b/streamly.cabal
@@ -288,7 +288,6 @@ library
                      , Streamly.Unfold
 
                     -- Folds
-                     , Streamly.Fold.Internal
                      , Streamly.Sink.Types
                      , Streamly.Sink
                      , Streamly.Pipe.Types