diff --git a/Data/List/Stream.hs b/Data/List/Stream.hs --- a/Data/List/Stream.hs +++ b/Data/List/Stream.hs @@ -10,14 +10,21 @@ -- -- A reimplementation of the standard Haskell list library to take advantage of -- stream fusion, and new GHC optimisations. The fusion mechanism is --- based on that described in: +-- based on stream fusion for sequences. Described in: -- --- /Rewriting Haskell Strings/, by Duncan Coutts, Don Stewart and +-- * /Stream Fusion: From Lists to Streams to Nothing at All/, by +-- Duncan Coutts, Roman Leshchinskiy and Don Stwwart, ICFP 2007. +-- +-- +-- * /Rewriting Haskell Strings/, by Duncan Coutts, Don Stewart and -- Roman Leshchinskiy, Practical Aspects of Declarative Languages -- 8th International Symposium, PADL 2007, 2007. --- -- -- +-- See the source for the complete story: +-- +-- * +-- -- This library is a drop in replacement for "Data.List". -- module Data.List.Stream ( @@ -629,9 +636,11 @@ -- | /O(n)/, /fusion/. A strict version of 'foldl'. foldl' :: (a -> b -> a) -> a -> [b] -> a foldl' f z0 xs0 = go z0 xs0 +#ifndef __HADDOCK__ where go !z [] = z go !z (x:xs) = go (f z x) xs +#endif {-# INLINE [1] foldl' #-} {-# RULES @@ -662,9 +671,11 @@ foldl1' :: (a -> a -> a) -> [a] -> a foldl1' _ [] = errorEmptyList "foldl1'" foldl1' f (x0:xs0) = go x0 xs0 +#ifndef __HADDOCK__ where go !z [] = z go !z (x:xs) = go (f z x) xs +#endif {-# INLINE [1] foldl1' #-} {-# RULES @@ -935,7 +946,7 @@ {-# RULES "strictMaximum -> fused" [~1] forall xs. - maximum xs = Stream.strictMaximum (stream xs) + strictMaximum xs = Stream.strictMaximum (stream xs) --"strictMaximum -> unfused" [1] forall xs. -- Stream.strictMaximum (stream xs) = strictMaximum xs #-} @@ -968,7 +979,7 @@ {-# RULES "strictMinimum -> fused" [~1] forall xs. - maximum xs = Stream.strictMinimum (stream xs) + strictMinimum xs = Stream.strictMinimum (stream xs) --"strictMinimum -> unfused" [1] forall xs. -- Stream.strictMinimum (stream xs) = strictMinimum xs #-} diff --git a/Data/Stream.hs b/Data/Stream.hs --- a/Data/Stream.hs +++ b/Data/Stream.hs @@ -1,4 +1,3 @@ --- #hide {-# OPTIONS_GHC -fdicts-cheap -fbang-patterns #-} -- | @@ -13,18 +12,24 @@ -- -- Stream fusion for sequences. Described in: -- --- /Rewriting Haskell Strings/, by Duncan Coutts, Don Stewart and +-- * /Stream Fusion: From Lists to Streams to Nothing at All/, by +-- Duncan Coutts, Roman Leshchinskiy and Don Stwwart, ICFP 2007. +-- +-- +-- * /Rewriting Haskell Strings/, by Duncan Coutts, Don Stewart and -- Roman Leshchinskiy, Practical Aspects of Declarative Languages -- 8th International Symposium, PADL 2007, 2007. +-- -- --- /Stream Fusion: From Lists to Streams to Nothing at All/, by --- Duncan Coutts, Roman Leshchinskiy and Don Stwwart, ICFP 2007. +-- See the source for the complete story: -- --- --- +-- * -- + module Data.Stream ( +#ifndef __HADDOCK__ + -- * The stream data type Stream(Stream), Step(..), @@ -225,9 +230,12 @@ bind, -- :: (a -> Bool) -> (a -> [b]) -> [a] -> [b] mapFilter, -- :: (a -> Bool) -> (a -> b) -> [a] -> [b] declare -- :: (a -> Stream b) -> a -> Stream b +#endif ) where +#ifndef __HADDOCK__ + #ifndef EXTERNAL_PACKAGE import {-# SOURCE #-} GHC.Err (error) @@ -294,61 +302,63 @@ instance Functor Stream where fmap = map --- A class of strict unlifted types. The Unlifted constraint in the Stream --- type above enforces a separation between user's types and the types used --- in stream states. +-- | A class of strict unlifted types. The Unlifted constraint in the +-- Stream type above enforces a separation between user's types and the +-- types used in stream states. -- class Unlifted a where - -- This expose function needs to be called in folds/loops that consume + -- | This expose function needs to be called in folds/loops that consume -- streams to expose the structure of the stream state to the simplifier -- In particular, to SpecConstr. -- expose :: a -> b -> b expose = seq - -- This makes GHC's optimiser happier; it sometimes produces really bad + -- | This makes GHC's optimiser happier; it sometimes produces really bad -- code for single-method dictionaries -- unlifted_dummy :: a unlifted_dummy = error "unlifted_dummy" -- --- Unlifted versions of () and Bool for use in Stream states. +-- | Unlifted versions of () and Bool for use in Stream states. -- data None = None instance Unlifted None +-- | A useful unlifted type data Switch = S1 | S2 instance Unlifted Switch --- Unlifted pairs, Maybe and Either +-- | Unlifted pairs, Maybe and Either -- data (Unlifted a, Unlifted b) => a :!: b = !a :!: !b instance (Unlifted a, Unlifted b) => Unlifted (a :!: b) where expose (a :!: b) s = expose a (expose b s) {-# INLINE expose #-} +-- | Unlifted Maybes data Unlifted a => Maybe a = Nothing | Just !a instance Unlifted a => Unlifted (Maybe a) where expose (Just a) s = expose a s expose Nothing s = s {-# INLINE expose #-} +-- | Unlifted sums data (Unlifted a, Unlifted b) => Either a b = Left !a | Right !b instance (Unlifted a, Unlifted b) => Unlifted (Either a b) where expose (Left a) s = expose a s expose (Right b) s = expose b s {-# INLINE expose #-} --- Some stream functions (notably concatMap) need to use a stream as a state +-- | Some stream functions (notably concatMap) need to use a stream as a state -- instance Unlifted (Stream a) where expose (Stream next s0) s = seq next (seq s0 s) {-# INLINE expose #-} - --- Boxes for user's state. This is the gateway for user's types into unlifted +-- | Boxes for user's state. This is the gateway for user's types into unlifted -- stream states. The L is always safe since it's lifted/lazy, exposing/seqing -- it does nothing. -- S is unlifted and so is only suitable for users states that we know we can @@ -1793,3 +1803,5 @@ moduleError :: String -> String -> a moduleError fun msg = error ("List." ++ fun ++ ':':' ':msg) {-# NOINLINE moduleError #-} + +#endif diff --git a/stream-fusion.cabal b/stream-fusion.cabal --- a/stream-fusion.cabal +++ b/stream-fusion.cabal @@ -1,5 +1,5 @@ Name: stream-fusion -Version: 0.1.2 +Version: 0.1.2.1 Author: Duncan Coutts, Don Stewart Maintainer: duncan.coutts@worc.ox.ac.uk, dons@galois.com License: BSD3 @@ -10,7 +10,7 @@ This package provides the standard Haskell list library reimplemented to allow stream fusion. This should in general provide faster list operations, and faster code for list-heavy - programs. See the paper "Stream Fusion: From Lists to Streams to Nothing at All", + programs. See the paper /Stream Fusion: From Lists to Streams to Nothing at All/, Coutts, Leshchinskiy and Stewart, 2007. To use, simply import Data.List.Stream in place of Data.List, and hide list functions from the Prelude. diff --git a/tests/Bench/StreamList.hs b/tests/Bench/StreamList.hs --- a/tests/Bench/StreamList.hs +++ b/tests/Bench/StreamList.hs @@ -148,8 +148,10 @@ -- * Special lists -- ** Functions on strings +{- unlines :: [String] -> String lines :: String -> [String] +-} {- words :: String -> [String] unwords :: [String] -> String @@ -225,7 +227,8 @@ -- ** Special folds concat = \ xs -> Stream.concat (s xs) -concatMap = \f xs -> Stream.concatMap f (s xs) + -- concatMap :: (a -> Stream b) -> Stream a -> Stream b +concatMap = \f xs -> u $ Stream.concatMap (s . f) (s xs) and = \ xs -> Stream.and (s xs) or = \ xs -> Stream.or (s xs) any = \f xs -> Stream.any f (s xs) @@ -343,8 +346,10 @@ -- * Special lists -- ** Functions on strings +{- unlines = \xs -> Stream.concatMap (\x -> x ++ ['\n']) (s xs) lines = \xs -> u (Stream.lines (s xs)) +-} {- words = Stream.words diff --git a/tests/Examples/SumReplicate.hs b/tests/Examples/SumReplicate.hs --- a/tests/Examples/SumReplicate.hs +++ b/tests/Examples/SumReplicate.hs @@ -1,6 +1,6 @@ module FuseTest where -import Data.List.Stream as L +import Data.List as L foo :: Int -> Int foo n = L.sum (L.replicate n 1)