%
-% (c) The GRASP/AQUA Project, Glasgow University, 1997
+% (c) The GRASP/AQUA Project, Glasgow University, 1997-1998
%
\section{String buffers}
Buffers for scanning string input stored in external arrays.
\begin{code}
-{-# OPTIONS -fno-prune-tydecls #-}
+
+{-# OPTIONS -optc-DNON_POSIX_SOURCE #-}
+
module StringBuffer
(
StringBuffer,
- -- creation
- hGetStringBuffer, -- :: FilePath -> IO StringBuffer
+ -- creation/destruction
+ hGetStringBuffer, -- :: FilePath -> IO StringBuffer
+ stringToStringBuffer, -- :: String -> IO StringBuffer
+ freeStringBuffer, -- :: StringBuffer -> IO ()
-- Lookup
currentChar, -- :: StringBuffer -> Char
lookAhead, -- :: StringBuffer -> Int -> Char
lookAhead#, -- :: StringBuffer -> Int# -> Char#
+ -- offsets
+ currentIndex#, -- :: StringBuffer -> Int#
+ lexemeIndex, -- :: StringBuffer -> Int#
+
-- moving the end point of the current lexeme.
- setCurrentPos#, -- :: StringBuffer -> Int# -> StringBuffer
- incLexeme, -- :: StringBuffer -> StringBuffer
- decLexeme, -- :: StringBuffer -> StringBuffer
+ addToCurrentPos, -- :: StringBuffer -> Int# -> StringBuffer
+ incCurrentPos, -- :: StringBuffer -> StringBuffer
+ decCurrentPos, -- :: StringBuffer -> StringBuffer
-- move the start and end lexeme pointer on by x units.
stepOn, -- :: StringBuffer -> StringBuffer
stepOnBy#, -- :: StringBuffer -> Int# -> StringBuffer
stepOnTo#, -- :: StringBuffer -> Int# -> StringBuffer
stepOnUntil, -- :: (Char -> Bool) -> StringBuffer -> StringBuffer
+ stepOnUntilChar#, -- :: StringBuffer -> Char# -> StringBuffer
stepOverLexeme, -- :: StringBuffer -> StringBuffer
scanNumLit, -- :: Int -> StringBuffer -> (Int, StringBuffer)
- expandWhile, -- :: (Char -> Bool) -> StringBuffer -> StringBuffer
+ squeezeLexeme, -- :: StringBuffer -> Int# -> StringBuffer
+ mergeLexemes, -- :: StringBuffer -> StringBuffer -> StringBuffer
+ expandWhile, -- :: (Char -> Bool) -> StringBuffer -> StringBuffer
+ expandWhile#, -- :: (Char# -> Bool) -> StringBuffer -> StringBuffer
expandUntilMatch, -- :: StrinBuffer -> String -> StringBuffer
-- at or beyond end of buffer?
bufferExhausted, -- :: StringBuffer -> Bool
-- matching
prefixMatch, -- :: StringBuffer -> String -> Bool
untilEndOfString#, -- :: StringBuffer -> Int#
- untilEndOfChar#, -- :: StringBuffer -> Int#
- untilChar#, -- :: StringBuffer -> Char# -> Int#
-- conversion
lexemeToString, -- :: StringBuffer -> String
- lexemeToByteArray, -- :: StringBuffer -> _ByteArray Int
lexemeToFastString, -- :: StringBuffer -> FastString
- lexemeToBuffer, -- :: StringBuffer -> StringBuffer
-
- FastString,
- ByteArray
) where
#include "HsVersions.h"
-import GlaExts
-import Addr ( Addr(..) )
-import Foreign
-import ST
-import IO ( openFile, hFileSize, hClose, IOMode(..)
-#if __GLASGOW_HASKELL__ >= 303
- , slurpFile
+
+#if __GLASGOW_HASKELL__ < 502
+import Panic ( panic )
+#else
+#if __GLASGOW_HASKELL__ < 503
+import Ptr ( Ptr(..) )
+#else
+import GHC.Ptr ( Ptr(..) )
#endif
- )
-#if __GLASGOW_HASKELL__ < 301
-import IOBase ( IOError(..), IOErrorType(..) )
-import IOHandle ( readHandle, writeHandle, filePtr )
-import PackBase ( unpackCStringBA )
+#endif
+
+#if __GLASGOW_HASKELL__ < 501
+import Char ( chr )
+#elif __GLASGOW_HASKELL__ < 503
+import PrelIO ( hGetcBuffered )
#else
-import PrelIOBase ( IOError(..), IOErrorType(..), haFO__ )
-import PrelHandle ( readHandle, writeHandle )
-import PrelPack ( unpackCStringBA )
+import GHC.IO ( hGetcBuffered )
#endif
import PrimPacked
import FastString
-import Char (isDigit)
+
+import GLAEXTS
+
+import Foreign
+
+#if __GLASGOW_HASKELL__ >= 502
+import CString ( newCString )
+#endif
+
+import IO ( openFile, isEOFError )
+import EXCEPTION ( bracket )
+
+#if __GLASGOW_HASKELL__ < 503
+import PrelIOBase
+import PrelHandle
+#else
+import GHC.IOBase
+import GHC.Handle
+#endif
+
+import Char ( isDigit )
\end{code}
\begin{code}
\end{code}
\begin{code}
-instance Text StringBuffer where
- showsPrec _ s = showString ""
+instance Show StringBuffer where
+ showsPrec _ s = showString "<stringbuffer>"
\end{code}
\begin{code}
hGetStringBuffer :: FilePath -> IO StringBuffer
-hGetStringBuffer fname =
-#if __GLASGOW_HASKELL__ >= 303
- slurpFile fname >>= \ (a , read) ->
- let (A# a#) = a
- (I# read#) = read
- in
- _casm_ `` ((char *)%0)[(int)%1]=(char)0; '' a (I# (read# -# 1#)) >>= \ () ->
- return (StringBuffer a# read# 0# 0#)
-#else
- openFile fname ReadMode >>= \ hndl ->
- hFileSize hndl >>= \ len@(J# _ _ d#) ->
- let len_i = fromInteger len in
- -- Allocate an array for system call to store its bytes into.
- -- ToDo: make it robust
--- trace (show ((len_i::Int)+1)) $
- _casm_ `` %r=(char *)malloc(sizeof(char)*(int)%0); '' (len_i::Int) >>= \ arr@(A# a#) ->
- if addr2Int# a# ==# 0# then
- fail (userError ("hGetStringBuffer: Could not allocate "++show len_i ++ " bytes"))
- else
- readHandle hndl >>= \ hndl_ ->
- writeHandle hndl hndl_ >>
- let ptr = filePtr hndl_ in
-#if __GLASGOW_HASKELL__ <= 302
- _ccall_ fread arr (1::Int) len_i (ptr::ForeignObj) >>= \ (I# read#) ->
+hGetStringBuffer fname = do
+ (a, read) <- slurpFileExpandTabs fname
+
+ -- urk! slurpFile gives us a buffer that doesn't have room for
+ -- the sentinel. Assume it has a final newline for now, and overwrite
+ -- that with the sentinel. slurpFileExpandTabs (below) leaves room
+ -- for the sentinel.
+ let (Ptr a#) = a;
+ (I# read#) = read;
+ end# = read# -# 1#
+
+ -- add sentinel '\NUL'
+ writeCharOffPtr a (I# end#) '\0'
+
+ return (StringBuffer a# end# 0# 0#)
+\end{code}
+
+-----------------------------------------------------------------------------
+-- Turn a String into a StringBuffer
+
+\begin{code}
+stringToStringBuffer :: String -> IO StringBuffer
+freeStringBuffer :: StringBuffer -> IO ()
+
+#if __GLASGOW_HASKELL__ >= 502
+stringToStringBuffer str = do
+ let sz@(I# sz#) = length str
+ Ptr a# <- newCString str
+ return (StringBuffer a# sz# 0# 0#)
+
+freeStringBuffer (StringBuffer a# _ _ _) = Foreign.free (Ptr a#)
#else
- _ccall_ fread arr (1::Int) len_i (ptr::Addr) >>= \ (I# read#) ->
+stringToStringBuffer = panic "stringToStringBuffer: not implemented"
+freeStringBuffer sb = return ()
#endif
- hClose hndl >>
- if read# ==# 0# then -- EOF or some other error
- fail (userError ("hGetStringBuffer: failed to slurp in interface file "++fname))
- else
- -- Add a sentinel NUL
- _casm_ `` ((char *)%0)[(int)%1]=(char)0; '' arr (I# (read# -# 1#)) >>= \ () ->
- return (StringBuffer a# read# 0# 0#)
+\end{code}
+
+-----------------------------------------------------------------------------
+This very disturbing bit of code is used for expanding the tabs in a
+file before we start parsing it. Expanding the tabs early makes the
+lexer a lot simpler: we only have to record the beginning of the line
+in order to be able to calculate the column offset of the current
+token.
+
+We guess the size of the buffer required as 20% extra for
+expanded tabs, and enlarge it if necessary.
+
+\begin{code}
+#if __GLASGOW_HASKELL__ < 501
+getErrType :: IO Int
+getErrType = _ccall_ getErrType__
+#endif
+
+slurpFileExpandTabs :: FilePath -> IO (Ptr (),Int)
+slurpFileExpandTabs fname = do
+ bracket (openFile fname ReadMode) (hClose)
+ (\ handle ->
+ do sz <- hFileSize handle
+ if sz > toInteger (maxBound::Int)
+ then ioError (userError "slurpFile: file too big")
+ else do
+ let sz_i = fromInteger sz
+ if sz_i == 0
+ -- empty file: just allocate a buffer containing '\0'
+ then do chunk <- allocMem 1
+ writeCharOffPtr chunk 0 '\0'
+ return (chunk, 0)
+ else do let sz_i' = (sz_i * 12) `div` 10 -- add 20% for tabs
+ chunk <- allocMem sz_i'
+ trySlurp handle sz_i' chunk
+ )
+
+trySlurp :: Handle -> Int -> Ptr () -> IO (Ptr (), Int)
+trySlurp handle sz_i chunk =
+#if __GLASGOW_HASKELL__ < 501
+ wantReadableHandle "hGetChar" handle $ \ handle_ ->
+ let fo = haFO__ handle_ in
+#else
+ wantReadableHandle "hGetChar" handle $
+ \ handle_@Handle__{ haFD=fd, haBuffer=ref, haBufferMode=mode } ->
+#endif
+ let
+ (I# chunk_sz) = sz_i
+
+ tAB_SIZE = 8#
+
+ slurpFile :: Int# -> Int# -> Ptr () -> Int# -> Int# -> IO (Ptr (), Int)
+ slurpFile c off chunk chunk_sz max_off = slurp c off
+ where
+
+ slurp :: Int# -> Int# -> IO (Ptr (), Int)
+ slurp c off | off >=# max_off = do
+ let new_sz = chunk_sz *# 2#
+ chunk' <- reAllocMem chunk (I# new_sz)
+ slurpFile c off chunk' new_sz (new_sz -# (tAB_SIZE +# 1#))
+ slurp c off = do
+#if __GLASGOW_HASKELL__ < 501
+ intc <- mayBlock fo (_ccall_ fileGetc fo)
+ if intc == ((-1)::Int)
+ then do errtype <- getErrType
+ if errtype == (19{-ERR_EOF-} :: Int)
+ then return (chunk, I# off)
+ else constructErrorAndFail "slurpFile"
+ else case chr intc of
+#else
+ buf <- readIORef ref
+ ch <- (if not (bufferEmpty buf)
+ then hGetcBuffered fd ref buf
+ else do
+#if __GLASGOW_HASKELL__ >= 503
+ new_buf <- fillReadBuffer fd True False buf
+#else
+ new_buf <- fillReadBuffer fd True buf
+#endif
+ hGetcBuffered fd ref new_buf)
+ `catch` \e -> if isEOFError e
+ then return '\xFFFF'
+ else ioError e
+ case ch of
+ '\xFFFF' -> return (chunk, I# off)
+#endif
+ '\t' -> tabIt c off
+ ch -> do writeCharOffPtr chunk (I# off) ch
+ let c' | ch == '\n' = 0#
+ | otherwise = c +# 1#
+ slurp c' (off +# 1#)
+
+ tabIt :: Int# -> Int# -> IO (Ptr (), Int)
+ -- can't run out of buffer in here, because we reserved an
+ -- extra tAB_SIZE bytes at the end earlier.
+ tabIt c off = do
+ writeCharOffPtr chunk (I# off) ' '
+ let c' = c +# 1#
+ off' = off +# 1#
+ if c' `remInt#` tAB_SIZE ==# 0#
+ then slurp c' off'
+ else tabIt c' off'
+ in do
+
+ -- allow space for a full tab at the end of the buffer
+ -- (that's what the max_off thing is for),
+ -- and add 1 to allow room for the final sentinel \NUL at
+ -- the end of the file.
+ (chunk', rc) <- slurpFile 0# 0# chunk chunk_sz (chunk_sz -# (tAB_SIZE +# 1#))
+ return (chunk', rc+1 {- room for sentinel -})
+
+
+reAllocMem :: Ptr () -> Int -> IO (Ptr ())
+reAllocMem ptr sz = do
+ chunk <- c_realloc ptr sz
+ if chunk == nullPtr
+ then fail "reAllocMem"
+ else return chunk
+
+allocMem :: Int -> IO (Ptr ())
+allocMem sz = do
+ chunk <- c_malloc sz
+ if chunk == nullPtr
+#if __GLASGOW_HASKELL__ < 501
+ then constructErrorAndFail "allocMem"
+#else
+ then ioException (IOError Nothing ResourceExhausted "malloc"
+ "out of memory" Nothing)
#endif
+ else return chunk
-unsafeWriteBuffer :: StringBuffer -> Int# -> Char# -> StringBuffer
-unsafeWriteBuffer s@(StringBuffer a _ _ _) i# ch# =
- unsafePerformIO (
- _casm_ `` ((char *)%0)[(int)%1]=(char)%2; '' (A# a) (I# i#) (C# ch#) >>= \ () ->
- return s
- )
+#if __GLASGOW_HASKELL__ <= 408
+c_malloc sz = do A# a <- c_malloc' sz; return (Ptr a)
+foreign import ccall "malloc" unsafe
+ c_malloc' :: Int -> IO Addr
+
+c_realloc (Ptr a) sz = do A# a <- c_realloc' (A# a) sz; return (Ptr a)
+foreign import ccall "realloc" unsafe
+ c_realloc' :: Addr -> Int -> IO Addr
+#else
+foreign import ccall "malloc" unsafe
+ c_malloc :: Int -> IO (Ptr a)
+
+foreign import ccall "realloc" unsafe
+ c_realloc :: Ptr a -> Int -> IO (Ptr a)
+#endif
\end{code}
Lookup
-- relative lookup, i.e, currentChar = lookAhead 0
lookAhead# (StringBuffer fo# _ _ c#) i# = indexCharOffAddr# fo# (c# +# i#)
+currentIndex# :: StringBuffer -> Int#
+currentIndex# (StringBuffer fo# _ _ c#) = c#
+
+lexemeIndex :: StringBuffer -> Int#
+lexemeIndex (StringBuffer fo# _ c# _) = c#
\end{code}
moving the start point of the current lexeme.
\begin{code}
-- moving the end point of the current lexeme.
-setCurrentPos# :: StringBuffer -> Int# -> StringBuffer
-setCurrentPos# (StringBuffer fo l# s# c#) i# =
+addToCurrentPos :: StringBuffer -> Int# -> StringBuffer
+addToCurrentPos (StringBuffer fo l# s# c#) i# =
StringBuffer fo l# s# (c# +# i#)
-- augmenting the current lexeme by one.
-incLexeme :: StringBuffer -> StringBuffer
-incLexeme (StringBuffer fo l# s# c#) = StringBuffer fo l# s# (c# +# 1#)
+incCurrentPos :: StringBuffer -> StringBuffer
+incCurrentPos (StringBuffer fo l# s# c#) = StringBuffer fo l# s# (c# +# 1#)
-decLexeme :: StringBuffer -> StringBuffer
-decLexeme (StringBuffer fo l# s# c#) = StringBuffer fo l# s# (c# -# 1#)
+decCurrentPos :: StringBuffer -> StringBuffer
+decCurrentPos (StringBuffer fo l# s# c#) = StringBuffer fo l# s# (c# -# 1#)
\end{code}
stepOnTo# :: StringBuffer -> Int# -> StringBuffer
stepOnTo# (StringBuffer fo l _ _) s# = StringBuffer fo l s# s#
+squeezeLexeme :: StringBuffer -> Int# -> StringBuffer
+squeezeLexeme (StringBuffer fo l s# c#) i# = StringBuffer fo l (s# +# i#) c#
+
+mergeLexemes :: StringBuffer -> StringBuffer -> StringBuffer
+mergeLexemes (StringBuffer fo l s# _) (StringBuffer _ _ _ c#)
+ = StringBuffer fo l s# c#
+
stepOnUntil :: (Char -> Bool) -> StringBuffer -> StringBuffer
stepOnUntil pred (StringBuffer fo l# s# c#) =
| ch# `eqChar#` '\NUL'# && c# >=# l# -> StringBuffer fo l# l# l# -- EOB, return immediately.
| otherwise -> StringBuffer fo l# s# c#
+expandWhile# :: (Char# -> Bool) -> StringBuffer -> StringBuffer
+expandWhile# pred (StringBuffer fo l# s# c#) =
+ loop c#
+ where
+ loop c# =
+ case indexCharOffAddr# fo c# of
+ ch# | pred ch# -> loop (c# +# 1#)
+ | ch# `eqChar#` '\NUL'# && c# >=# l# -> StringBuffer fo l# s# c# -- EOB, return immediately.
+ | otherwise -> StringBuffer fo l# s# c#
-scanNumLit :: Int -> StringBuffer -> (Int,StringBuffer)
-scanNumLit (I# acc#) (StringBuffer fo l# s# c#) =
- loop acc# c#
+scanNumLit :: Integer -> StringBuffer -> (Integer,StringBuffer)
+scanNumLit acc (StringBuffer fo l# s# c#) =
+ loop acc c#
where
- loop acc# c# =
+ loop acc c# =
case indexCharOffAddr# fo c# of
- ch# | isDigit (C# ch#) -> loop (acc# *# 10# +# (ord# ch# -# ord# '0'#)) (c# +# 1#)
- | ch# `eqChar#` '\NUL'# && c# >=# l# -> (I# acc#, StringBuffer fo l# l# l#) -- EOB, return immediately.
- | otherwise -> (I# acc#,StringBuffer fo l# s# c#)
+ ch# | isDigit (C# ch#) -> loop (acc*10 + (toInteger (I# (ord# ch# -# ord# '0'#)))) (c# +# 1#)
+ | ch# `eqChar#` '\NUL'# && c# >=# l# -> (acc, StringBuffer fo l# s# c#) -- EOB, return immediately.
+ | otherwise -> (acc,StringBuffer fo l# s# c#)
-expandUntilMatch :: StringBuffer -> String -> StringBuffer
+expandUntilMatch :: StringBuffer -> String -> Maybe StringBuffer
expandUntilMatch (StringBuffer fo l# s# c#) str =
loop c# str
where
- loop c# [] = StringBuffer fo l# s# c#
- loop c# ((C# x#):xs)
- | indexCharOffAddr# fo c# `eqChar#` x#
- = loop (c# +# 1#) xs
- | otherwise
- = loop (c# +# 1#) str
+ loop c# [] = Just (StringBuffer fo l# s# c#)
+ loop c# ((C# x#):xs) =
+ case indexCharOffAddr# fo c# of
+ ch# | ch# `eqChar#` '\NUL'# && c# >=# l# -> Nothing
+ | ch# `eqChar#` x# -> loop (c# +# 1#) xs
+ | otherwise -> loop (c# +# 1#) str
\end{code}
_ -> loop (c# +# 1#)
-untilEndOfChar# :: StringBuffer -> StringBuffer
-untilEndOfChar# (StringBuffer fo l# s# c#) =
- loop c#
- where
- getch# i# = indexCharOffAddr# fo i#
-
- loop c# =
- case getch# c# of
- '\''# ->
- case getch# (c# -# 1#) of
- '\\'# ->
- case getch# (c# -# 2#) of
- '\\'# -> -- end of char
- StringBuffer fo l# s# c#
- _ -> loop (c# +# 1#) -- false alarm
- _ -> StringBuffer fo l# s# c#
- '\NUL'# ->
- if c# >=# l# then -- hit sentinel, this doesn't look too good..
- StringBuffer fo l# l# l#
- else
- loop (c# +# 1#)
- _ -> loop (c# +# 1#)
-
-untilChar# :: StringBuffer -> Char# -> StringBuffer
-untilChar# (StringBuffer fo l# s# c#) x# =
+stepOnUntilChar# :: StringBuffer -> Char# -> StringBuffer
+stepOnUntilChar# (StringBuffer fo l# s# c#) x# =
loop c#
where
loop c#
- | indexCharOffAddr# fo c# `eqChar#` x#
- = StringBuffer fo l# s# c#
+ | c# >=# l# || indexCharOffAddr# fo c# `eqChar#` x#
+ = StringBuffer fo l# c# c#
| otherwise
= loop (c# +# 1#)
-- conversion
lexemeToString :: StringBuffer -> String
-lexemeToString (StringBuffer fo _ start_pos# current#) =
+lexemeToString (StringBuffer fo len# start_pos# current#) =
if start_pos# ==# current# then
""
else
- unpackCStringBA (copySubStr (A# fo) (I# start_pos#) (I# (current# -# start_pos#)))
-
-lexemeToByteArray :: StringBuffer -> _ByteArray Int
-lexemeToByteArray (StringBuffer fo _ start_pos# current#) =
- if start_pos# ==# current# then
- error "lexemeToByteArray"
- else
- copySubStr (A# fo) (I# start_pos#) (I# (current# -# start_pos#))
+ let len = I# (current# -# start_pos#) in
+ unpackNBytesBA (copySubStr fo (I# start_pos#) len) len
lexemeToFastString :: StringBuffer -> FastString
lexemeToFastString (StringBuffer fo l# start_pos# current#) =
if start_pos# ==# current# then
- mkFastCharString2 (A# fo) (I# 0#)
- else
- mkFastSubString (A# fo) (I# start_pos#) (I# (current# -# start_pos#))
-
-{-
- Create a StringBuffer from the current lexeme, and add a sentinel
- at the end. Know What You're Doing before taking this function
- into use..
--}
-lexemeToBuffer :: StringBuffer -> StringBuffer
-lexemeToBuffer (StringBuffer fo l# start_pos# current#) =
- if start_pos# ==# current# then
- StringBuffer fo 0# start_pos# current# -- an error, really.
+ mkFastString ""
else
- unsafeWriteBuffer (StringBuffer fo (current# -# start_pos#) start_pos# start_pos#)
- (current# -# 1#)
- '\NUL'#
-
+ mkFastSubString fo (I# start_pos#) (I# (current# -# start_pos#))
\end{code}