-----------------------------------------------------------------------------
---
+-- |
-- Module : Text.Regex.Posix
--- Copyright : (c) The University of Glasgow 2001
--- License : BSD-style (see the file libraries/core/LICENSE)
+-- Copyright : (c) The University of Glasgow 2002
+-- License : BSD-style (see the file libraries/base/LICENSE)
--
-- Maintainer : libraries@haskell.org
-- Stability : experimental
--- Portability : non-portable (only on platforms that provide POSIX regexps)
---
--- $Id: Posix.hsc,v 1.4 2002/02/13 11:52:42 simonmar Exp $
+-- Portability : portable
--
-- Interface to the POSIX regular expression library.
--- ToDo: should have an interface using PackedStrings.
--
-----------------------------------------------------------------------------
+-- ToDo: should have an interface using PackedStrings.
+#ifndef __NHC__
+#include "HsBaseConfig.h"
+#else
+#define HAVE_REGEX_H 1
+#define HAVE_REGCOMP 1
+#endif
+
module Text.Regex.Posix (
+ -- * The @Regex@ type
Regex, -- abstract
+ -- * Compiling a regular expression
regcomp, -- :: String -> Int -> IO Regex
+ -- ** Flags for regcomp
+ regExtended, -- (flag to regcomp) use extended regex syntax
+ regIgnoreCase, -- (flag to regcomp) ignore case when matching
+ regNewline, -- (flag to regcomp) '.' doesn't match newline
+
+ -- * Matching a regular expression
regexec, -- :: Regex -- pattern
-- -> String -- string to match
-- -> IO (Maybe (String, -- everything before match
-- String, -- everything after match
-- [String])) -- subexpression matches
- regExtended, -- (flag to regcomp) use extended regex syntax
- regIgnoreCase, -- (flag to regcomp) ignore case when matching
- regNewline -- (flag to regcomp) '.' doesn't match newline
) where
+#include <sys/types.h>
+
+#if HAVE_REGEX_H && HAVE_REGCOMP
#include "regex.h"
+#else
+#include "regex/regex.h"
+
+-- CFILES stuff is Hugs only
+{-# CFILES cbits/regex/reallocf.c #-}
+{-# CFILES cbits/regex/regcomp.c #-}
+{-# CFILES cbits/regex/regerror.c #-}
+{-# CFILES cbits/regex/regexec.c #-}
+{-# CFILES cbits/regex/regfree.c #-}
+#endif
import Prelude
import Foreign
import Foreign.C
+type CRegex = ()
+
+-- | A compiled regular expression
newtype Regex = Regex (ForeignPtr CRegex)
-- -----------------------------------------------------------------------------
-- regcomp
-regcomp :: String -> Int -> IO Regex
+-- | Compiles a regular expression
+regcomp
+ :: String -- ^ The regular expression to compile
+ -> Int -- ^ Flags (summed together)
+ -> IO Regex -- ^ Returns: the compiled regular expression
regcomp pattern flags = do
- regex_ptr <- mallocBytes (#const sizeof(regex_t))
- regex_fptr <- newForeignPtr regex_ptr (regfree regex_ptr)
+ regex_fptr <- mallocForeignPtrBytes (#const sizeof(regex_t))
r <- withCString pattern $ \cstr ->
withForeignPtr regex_fptr $ \p ->
c_regcomp p cstr (fromIntegral flags)
if (r == 0)
- then return (Regex regex_fptr)
+ then do addForeignPtrFinalizer ptr_regfree regex_fptr
+ return (Regex regex_fptr)
else error "Text.Regex.Posix.regcomp: error in pattern" -- ToDo
-regfree :: Ptr CRegex -> IO ()
-regfree p_regex = do
- c_regfree p_regex
- free p_regex
-
-- -----------------------------------------------------------------------------
-- regexec
-regexec :: Regex -- pattern
- -> String -- string to match
- -> IO (Maybe (String, -- everything before match
- String, -- matched portion
- String, -- everything after match
- [String])) -- subexpression matches
+-- | Matches a regular expression against a string
+regexec :: Regex -- ^ Compiled regular expression
+ -> String -- ^ String to match against
+ -> IO (Maybe (String, String, String, [String]))
+ -- ^ Returns: 'Nothing' if the regex did not match the
+ -- string, or:
+ --
+ -- @
+ -- 'Just' (everything before match,
+ -- matched portion,
+ -- everything after match,
+ -- subexpression matches)
+ -- @
regexec (Regex regex_fptr) str = do
withCString str $ \cstr -> do
if (r /= 0) then return Nothing else do
- (before,match,after) <- matched_parts str p_match
+ (before,match,after) <- matched_parts str p_match
- sub_strs <-
- mapM (unpack str) $ take nsub_int $ tail $
- iterate (`plusPtr` (#const sizeof(regmatch_t))) p_match
+ sub_strs <-
+ mapM (unpack str) $ take nsub_int $ tail $
+ iterate (`plusPtr` (#const sizeof(regmatch_t))) p_match
- return (Just (before, match, after, sub_strs))
+ return (Just (before, match, after, sub_strs))
matched_parts :: String -> Ptr CRegMatch -> IO (String, String, String)
matched_parts string p_match = do
- start <- (#peek regmatch_t, rm_so) p_match :: IO CInt
- end <- (#peek regmatch_t, rm_eo) p_match :: IO CInt
+ start <- (#peek regmatch_t, rm_so) p_match :: IO (#type regoff_t)
+ end <- (#peek regmatch_t, rm_eo) p_match :: IO (#type regoff_t)
let s = fromIntegral start; e = fromIntegral end
- return ( take (s-1) string,
+ return ( take s string,
take (e-s) (drop s string),
drop e string )
unpack :: String -> Ptr CRegMatch -> IO (String)
unpack string p_match = do
- start <- (#peek regmatch_t, rm_so) p_match :: IO CInt
- end <- (#peek regmatch_t, rm_eo) p_match :: IO CInt
+ start <- (#peek regmatch_t, rm_so) p_match :: IO (#type regoff_t)
+ end <- (#peek regmatch_t, rm_eo) p_match :: IO (#type regoff_t)
-- the subexpression may not have matched at all, perhaps because it
-- was optional. In this case, the offsets are set to -1.
if (start == -1) then return "" else do
- return (take (fromIntegral (end-start)) (drop (fromIntegral start) string))
+ return (take (fromIntegral (end-start)) (drop (fromIntegral start) string))
-- -----------------------------------------------------------------------------
-- The POSIX regex C interface
-- Flags for regexec
#enum Int,, \
REG_NOTBOL, \
- REG_NOTEOL \
+ REG_NOTEOL
-- Return values from regexec
#enum Int,, \
REG_ERANGE, \
REG_ESPACE
-type CRegex = ()
type CRegMatch = ()
-foreign import "regcomp" unsafe
+-- GHC and Hugs get the appropriate include file from the OPTIONS
+-- pragma generated by hsc2hs from the above #include.
+-- Implementations following the FFI spec have to specify it in the
+-- foreign import, which is awkward because some systems provide
+-- regex.h and the rest of the regex library, but otherwise we
+-- need to use our own copy, regex/regex.h.
+
+#if __GLASGOW_HASKELL__ || __HUGS__
+foreign import ccall unsafe "regcomp"
+ c_regcomp :: Ptr CRegex -> CString -> CInt -> IO CInt
+
+foreign import ccall unsafe "®free"
+ ptr_regfree :: FunPtr (Ptr CRegex -> IO ())
+
+foreign import ccall unsafe "regexec"
+ c_regexec :: Ptr CRegex -> CString -> CSize
+ -> Ptr CRegMatch -> CInt -> IO CInt
+#elif HAVE_REGEX_H && HAVE_REGCOMP
+foreign import ccall unsafe "regex.h regcomp"
+ c_regcomp :: Ptr CRegex -> CString -> CInt -> IO CInt
+
+foreign import ccall unsafe "regex.h ®free"
+ ptr_regfree :: FunPtr (Ptr CRegex -> IO ())
+
+foreign import ccall unsafe "regex.h regexec"
+ c_regexec :: Ptr CRegex -> CString -> CSize
+ -> Ptr CRegMatch -> CInt -> IO CInt
+#else
+foreign import ccall unsafe "regex/regex.h regcomp"
c_regcomp :: Ptr CRegex -> CString -> CInt -> IO CInt
-foreign import "regfree" unsafe
- c_regfree :: Ptr CRegex -> IO ()
+foreign import ccall unsafe "regex/regex.h ®free"
+ ptr_regfree :: FunPtr (Ptr CRegex -> IO ())
-foreign import "regexec" unsafe
+foreign import ccall unsafe "regex/regex.h regexec"
c_regexec :: Ptr CRegex -> CString -> CSize
-> Ptr CRegMatch -> CInt -> IO CInt
+#endif
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