+++ /dev/null
------------------------------------------------------------------------------
--- |
--- Module : Data.PackedString
--- Copyright : (c) The University of Glasgow 2001
--- License : BSD-style (see the file libraries/base/LICENSE)
---
--- Maintainer : libraries@haskell.org
--- Stability : experimental
--- Portability : portable
---
--- This API is deprecated. You might be able to use "Data.ByteString"
--- or "Data.ByteString.Char8", provided you don't need full Unicode support.
--- The long term aim is to provide a Unicode layer on "Data.ByteString",
--- and then to provide a replacement for this "Data.PackedString" API based on
--- that.
---
------------------------------------------------------------------------------
-
--- Original GHC implementation by Bryan O\'Sullivan,
--- rewritten to use UArray by Simon Marlow.
-
-module Data.PackedString
- {-# DEPRECATED "use Data.ByteString, Data.ByteString.Char8, or plain String." #-}
- (
- -- * The @PackedString@ type
- PackedString, -- abstract, instances: Eq, Ord, Show, Typeable
-
- -- * Converting to and from @PackedString@s
- packString, -- :: String -> PackedString
- unpackPS, -- :: PackedString -> String
-
-#ifndef __NHC__
- -- * I\/O with @PackedString@s
- hPutPS, -- :: Handle -> PackedString -> IO ()
- hGetPS, -- :: Handle -> Int -> IO PackedString
-#endif
-
- -- * List-like manipulation functions
- nilPS, -- :: PackedString
- consPS, -- :: Char -> PackedString -> PackedString
- headPS, -- :: PackedString -> Char
- tailPS, -- :: PackedString -> PackedString
- nullPS, -- :: PackedString -> Bool
- appendPS, -- :: PackedString -> PackedString -> PackedString
- lengthPS, -- :: PackedString -> Int
- indexPS, -- :: PackedString -> Int -> Char
- mapPS, -- :: (Char -> Char) -> PackedString -> PackedString
- filterPS, -- :: (Char -> Bool) -> PackedString -> PackedString
- reversePS, -- :: PackedString -> PackedString
- concatPS, -- :: [PackedString] -> PackedString
- elemPS, -- :: Char -> PackedString -> Bool
- substrPS, -- :: PackedString -> Int -> Int -> PackedString
- takePS, -- :: Int -> PackedString -> PackedString
- dropPS, -- :: Int -> PackedString -> PackedString
- splitAtPS, -- :: Int -> PackedString -> (PackedString, PackedString)
-
- foldlPS, -- :: (a -> Char -> a) -> a -> PackedString -> a
- foldrPS, -- :: (Char -> a -> a) -> a -> PackedString -> a
- takeWhilePS, -- :: (Char -> Bool) -> PackedString -> PackedString
- dropWhilePS, -- :: (Char -> Bool) -> PackedString -> PackedString
- spanPS, -- :: (Char -> Bool) -> PackedString -> (PackedString, PackedString)
- breakPS, -- :: (Char -> Bool) -> PackedString -> (PackedString, PackedString)
- linesPS, -- :: PackedString -> [PackedString]
- unlinesPS, -- :: [PackedString] -> PackedString
- wordsPS, -- :: PackedString -> [PackedString]
- unwordsPS, -- :: [PackedString] -> PackedString
- splitPS, -- :: Char -> PackedString -> [PackedString]
- splitWithPS, -- :: (Char -> Bool) -> PackedString -> [PackedString]
-
- joinPS, -- :: PackedString -> [PackedString] -> PackedString
-
- ) where
-
-import Prelude
-
-#ifndef __NHC__
-
-import Data.Array.Unboxed
-import Data.Array.IO
-import Data.Typeable
-import Data.Char
-#ifdef __GLASGOW_HASKELL__
-import Data.Generics
-#endif
-
-import System.IO
-
--- -----------------------------------------------------------------------------
--- PackedString type declaration
-
--- | A space-efficient representation of a 'String', which supports various
--- efficient operations. A 'PackedString' contains full Unicode 'Char's.
-newtype PackedString = PS (UArray Int Char)
-
--- ToDo: we could support "slices", i.e. include offset and length fields into
--- the string, so that operations like take/drop could be O(1). Perhaps making
--- a slice should be conditional on the ratio of the slice/string size to
--- limit memory leaks.
-
-instance Eq PackedString where
- (PS x) == (PS y) = x == y
-
-instance Ord PackedString where
- compare (PS x) (PS y) = compare x y
-
---instance Read PackedString: ToDo
-
-instance Show PackedString where
- showsPrec p ps r = showsPrec p (unpackPS ps) r
-
-#include "Typeable.h"
-INSTANCE_TYPEABLE0(PackedString,packedStringTc,"PackedString")
-
--- -----------------------------------------------------------------------------
--- Constructor functions
-
--- | The 'nilPS' value is the empty string.
-nilPS :: PackedString
-nilPS = PS (array (0,-1) [])
-
--- | The 'consPS' function prepends the given character to the
--- given string.
-consPS :: Char -> PackedString -> PackedString
-consPS c cs = packString (c : (unpackPS cs)) -- ToDo:better
-
--- | Convert a 'String' into a 'PackedString'
-packString :: String -> PackedString
-packString str = packNChars (length str) str
-
--- | The 'packNChars' function creates a 'PackedString' out of the
--- first @len@ elements of the given 'String'.
-packNChars :: Int -> [Char] -> PackedString
-packNChars len str = PS (listArray (0,len-1) str)
-
--- -----------------------------------------------------------------------------
--- Destructor functions (taking PackedStrings apart)
-
--- | Convert a 'PackedString' into a 'String'
-unpackPS :: PackedString -> String
-unpackPS (PS ps) = elems ps
-
--- -----------------------------------------------------------------------------
--- List-mimicking functions for PackedStrings
-
--- | The 'lengthPS' function returns the length of the input list. Analogous to 'length'.
-lengthPS :: PackedString -> Int
-lengthPS (PS ps) = rangeSize (bounds ps)
-
--- | The 'indexPS' function returns the character in the string at the given position.
-indexPS :: PackedString -> Int -> Char
-indexPS (PS ps) i = ps ! i
-
--- | The 'headPS' function returns the first element of a 'PackedString' or throws an
--- error if the string is empty.
-headPS :: PackedString -> Char
-headPS ps
- | nullPS ps = error "Data.PackedString.headPS: head []"
- | otherwise = indexPS ps 0
-
--- | The 'tailPS' function returns the tail of a 'PackedString' or throws an error
--- if the string is empty.
-tailPS :: PackedString -> PackedString
-tailPS ps
- | len <= 0 = error "Data.PackedString.tailPS: tail []"
- | len == 1 = nilPS
- | otherwise = substrPS ps 1 (len - 1)
- where
- len = lengthPS ps
-
--- | The 'nullPS' function returns True iff the argument is null.
-nullPS :: PackedString -> Bool
-nullPS (PS ps) = rangeSize (bounds ps) == 0
-
--- | The 'appendPS' function appends the second string onto the first.
-appendPS :: PackedString -> PackedString -> PackedString
-appendPS xs ys
- | nullPS xs = ys
- | nullPS ys = xs
- | otherwise = concatPS [xs,ys]
-
--- | The 'mapPS' function applies a function to each character in the string.
-mapPS :: (Char -> Char) -> PackedString -> PackedString
-mapPS f (PS ps) = PS (amap f ps)
-
--- | The 'filterPS' function filters out the appropriate substring.
-filterPS :: (Char -> Bool) -> PackedString -> PackedString {-or String?-}
-filterPS pred ps = packString (filter pred (unpackPS ps))
-
--- | The 'foldlPS' function behaves like 'foldl' on 'PackedString's.
-foldlPS :: (a -> Char -> a) -> a -> PackedString -> a
-foldlPS f b ps = foldl f b (unpackPS ps)
-
--- | The 'foldrPS' function behaves like 'foldr' on 'PackedString's.
-foldrPS :: (Char -> a -> a) -> a -> PackedString -> a
-foldrPS f v ps = foldr f v (unpackPS ps)
-
--- | The 'takePS' function takes the first @n@ characters of a 'PackedString'.
-takePS :: Int -> PackedString -> PackedString
-takePS n ps = substrPS ps 0 (n-1)
-
--- | The 'dropPS' function drops the first @n@ characters of a 'PackedString'.
-dropPS :: Int -> PackedString -> PackedString
-dropPS n ps = substrPS ps n (lengthPS ps - 1)
-
--- | The 'splitWithPS' function splits a 'PackedString' at a given index.
-splitAtPS :: Int -> PackedString -> (PackedString, PackedString)
-splitAtPS n ps = (takePS n ps, dropPS n ps)
-
--- | The 'takeWhilePS' function is analogous to the 'takeWhile' function.
-takeWhilePS :: (Char -> Bool) -> PackedString -> PackedString
-takeWhilePS pred ps = packString (takeWhile pred (unpackPS ps))
-
--- | The 'dropWhilePS' function is analogous to the 'dropWhile' function.
-dropWhilePS :: (Char -> Bool) -> PackedString -> PackedString
-dropWhilePS pred ps = packString (dropWhile pred (unpackPS ps))
-
--- | The 'elemPS' function returns True iff the given element is in the string.
-elemPS :: Char -> PackedString -> Bool
-elemPS c ps = c `elem` unpackPS ps
-
--- | The 'spanPS' function returns a pair containing the result of
--- running both 'takeWhilePS' and 'dropWhilePS'.
-spanPS :: (Char -> Bool) -> PackedString -> (PackedString, PackedString)
-spanPS p ps = (takeWhilePS p ps, dropWhilePS p ps)
-
--- | The 'breakPS' function breaks a string at the first position which
--- satisfies the predicate.
-breakPS :: (Char -> Bool) -> PackedString -> (PackedString, PackedString)
-breakPS p ps = spanPS (not . p) ps
-
--- | The 'linesPS' function splits the input on line-breaks.
-linesPS :: PackedString -> [PackedString]
-linesPS ps = splitPS '\n' ps
-
--- | The 'unlinesPS' function concatenates the input list after
--- interspersing newlines.
-unlinesPS :: [PackedString] -> PackedString
-unlinesPS = joinPS (packString "\n")
-
--- | The 'wordsPS' function is analogous to the 'words' function.
-wordsPS :: PackedString -> [PackedString]
-wordsPS ps = filter (not.nullPS) (splitWithPS isSpace ps)
-
--- | The 'unwordsPS' function is analogous to the 'unwords' function.
-unwordsPS :: [PackedString] -> PackedString
-unwordsPS = joinPS (packString " ")
-
--- | The 'reversePS' function reverses the string.
-reversePS :: PackedString -> PackedString
-reversePS ps = packString (reverse (unpackPS ps))
-
--- | The 'concatPS' function concatenates a list of 'PackedString's.
-concatPS :: [PackedString] -> PackedString
-concatPS pss = packString (concat (map unpackPS pss))
-
-------------------------------------------------------------
-
--- | The 'joinPS' function takes a 'PackedString' and a list of 'PackedString's
--- and concatenates the list after interspersing the first argument between
--- each element of the list.
-joinPS :: PackedString -> [PackedString] -> PackedString
-joinPS filler pss = concatPS (splice pss)
- where
- splice [] = []
- splice [x] = [x]
- splice (x:y:xs) = x:filler:splice (y:xs)
-
--- ToDo: the obvious generalisation
-{-
- Some properties that hold:
-
- * splitPS x ls = ls'
- where False = any (map (x `elemPS`) ls')
-
- * joinPS (packString [x]) (splitPS x ls) = ls
--}
-
--- | The 'splitPS' function splits the input string on each occurrence of the given 'Char'.
-splitPS :: Char -> PackedString -> [PackedString]
-splitPS c = splitWithPS (== c)
-
--- | The 'splitWithPS' function takes a character predicate and splits the input string
--- at each character which satisfies the predicate.
-splitWithPS :: (Char -> Bool) -> PackedString -> [PackedString]
-splitWithPS pred (PS ps) =
- splitify 0
- where
- len = lengthPS (PS ps)
-
- splitify n
- | n >= len = []
- | otherwise =
- let
- break_pt = first_pos_that_satisfies pred ps len n
- in
- if break_pt == n then -- immediate match, empty substring
- nilPS
- : splitify (break_pt + 1)
- else
- substrPS (PS ps) n (break_pt - 1) -- leave out the matching character
- : splitify (break_pt + 1)
-
-first_pos_that_satisfies pred ps len n =
- case [ m | m <- [n..len-1], pred (ps ! m) ] of
- [] -> len
- (m:_) -> m
-
--- -----------------------------------------------------------------------------
--- Local utility functions
-
--- The definition of @_substrPS@ is essentially:
--- @take (end - begin + 1) (drop begin str)@.
-
--- | The 'substrPS' function takes a 'PackedString' and two indices
--- and returns the substring of the input string between (and including)
--- these indices.
-substrPS :: PackedString -> Int -> Int -> PackedString
-substrPS (PS ps) begin end = packString [ ps ! i | i <- [begin..end] ]
-
--- -----------------------------------------------------------------------------
--- hPutPS
-
--- | Outputs a 'PackedString' to the specified 'Handle'.
---
--- NOTE: the representation of the 'PackedString' in the file is assumed to
--- be in the ISO-8859-1 encoding. In other words, only the least significant
--- byte is taken from each character in the 'PackedString'.
-hPutPS :: Handle -> PackedString -> IO ()
-hPutPS h (PS ps) = do
- let l = lengthPS (PS ps)
- arr <- newArray_ (0, l-1)
- sequence_ [ writeArray arr i (fromIntegral (ord (ps ! i))) | i <- [0..l-1] ]
- hPutArray h arr l
-
--- -----------------------------------------------------------------------------
--- hGetPS
-
--- | Read a 'PackedString' directly from the specified 'Handle'.
--- This is far more efficient than reading the characters into a 'String'
--- and then using 'packString'.
---
--- NOTE: as with 'hPutPS', the string representation in the file is
--- assumed to be ISO-8859-1.
-hGetPS :: Handle -> Int -> IO PackedString
-hGetPS h i = do
- arr <- newArray_ (0, i-1)
- l <- hGetArray h arr i
- chars <- mapM (\i -> readArray arr i >>= return.chr.fromIntegral) [0..l-1]
- return (packNChars l chars)
-
-#else /* __NHC__ */
-
---import Prelude hiding (append, break, concat, cons, drop, dropWhile,
--- filter, foldl, foldr, head, length, lines, map,
--- nil, null, reverse, span, splitAt, subst, tail,
--- take, takeWhile, unlines, unwords, words)
--- also hiding: Ix(..), Functor(..)
-import qualified NHC.PackedString
-import NHC.PackedString (PackedString,packString,unpackPS)
-import List (intersperse)
-
-
-nilPS :: PackedString
-consPS :: Char -> PackedString -> PackedString
-headPS :: PackedString -> Char
-tailPS :: PackedString -> PackedString
-nullPS :: PackedString -> Bool
-appendPS :: PackedString -> PackedString -> PackedString
-lengthPS :: PackedString -> Int
-indexPS :: PackedString -> Int -> Char
-mapPS :: (Char -> Char) -> PackedString -> PackedString
-filterPS :: (Char -> Bool) -> PackedString -> PackedString
-reversePS :: PackedString -> PackedString
-concatPS :: [PackedString] -> PackedString
-elemPS :: Char -> PackedString -> Bool
-substrPS :: PackedString -> Int -> Int -> PackedString
-takePS :: Int -> PackedString -> PackedString
-dropPS :: Int -> PackedString -> PackedString
-splitAtPS :: Int -> PackedString -> (PackedString, PackedString)
-
-foldlPS :: (a -> Char -> a) -> a -> PackedString -> a
-foldrPS :: (Char -> a -> a) -> a -> PackedString -> a
-takeWhilePS :: (Char -> Bool) -> PackedString -> PackedString
-dropWhilePS :: (Char -> Bool) -> PackedString -> PackedString
-spanPS :: (Char -> Bool) -> PackedString -> (PackedString, PackedString)
-breakPS :: (Char -> Bool) -> PackedString -> (PackedString, PackedString)
-linesPS :: PackedString -> [PackedString]
-unlinesPS :: [PackedString] -> PackedString
-
-wordsPS :: PackedString -> [PackedString]
-unwordsPS :: [PackedString] -> PackedString
-splitPS :: Char -> PackedString -> [PackedString]
-splitWithPS :: (Char -> Bool) -> PackedString -> [PackedString]
-joinPS :: PackedString -> [PackedString] -> PackedString
-
-nilPS = NHC.PackedString.nil
-consPS = NHC.PackedString.cons
-headPS = NHC.PackedString.head
-tailPS = NHC.PackedString.tail
-nullPS = NHC.PackedString.null
-appendPS = NHC.PackedString.append
-lengthPS = NHC.PackedString.length
-indexPS p i = (unpackPS p) !! i
-mapPS = NHC.PackedString.map
-filterPS = NHC.PackedString.filter
-reversePS = NHC.PackedString.reverse
-concatPS = NHC.PackedString.concat
-elemPS c p = c `elem` unpackPS p
-substrPS = NHC.PackedString.substr
-takePS = NHC.PackedString.take
-dropPS = NHC.PackedString.drop
-splitAtPS = NHC.PackedString.splitAt
-
-foldlPS = NHC.PackedString.foldl
-foldrPS = NHC.PackedString.foldr
-takeWhilePS = NHC.PackedString.takeWhile
-dropWhilePS = NHC.PackedString.dropWhile
-spanPS = NHC.PackedString.span
-breakPS = NHC.PackedString.break
-linesPS = NHC.PackedString.lines
-unlinesPS = NHC.PackedString.unlines
-
-wordsPS = NHC.PackedString.words
-unwordsPS = NHC.PackedString.unwords
-splitPS c = splitWithPS (==c)
-splitWithPS p =
- map packString . split' p [] . unpackPS
- where
- split' :: (Char->Bool) -> String -> String -> [String]
- split' pred [] [] = []
- split' pred acc [] = [reverse acc]
- split' pred acc (x:xs) | pred x = reverse acc: split' pred [] xs
- | otherwise = split' pred (x:acc) xs
-
-joinPS sep = concatPS . intersperse sep
-
-#endif
-
-#ifdef __GLASGOW_HASKELL__
-instance Data PackedString where
- gunfold k z c = error "gunfold"
- toConstr (PS _) = con_PS
- dataTypeOf _ = ty_PackedString
-
-con_PS = mkConstr ty_PackedString "PS" [] Prefix
-ty_PackedString = mkDataType "Data.PackedString.PackedString" [con_PS]
-#endif
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