[project @ 2001-08-02 11:20:50 by simonmar]

[ghc-base.git] / Text / Regex.hs

diff --git a/Text/Regex.hs b/Text/Regex.hs
new file mode 100644 (file)
index 0000000..c7731d2
--- /dev/null
+++ b/Text/Regex.hs
@@ -0,0 +1,58 @@
+-----------------------------------------------------------------------------
+-- 
+-- Module      :  Text.Regex
+-- Copyright   :  (c) The University of Glasgow 2001
+-- License     :  BSD-style (see the file libraries/core/LICENSE)
+-- 
+-- Maintainer  :  libraries@haskell.org
+-- Stability   :  experimental
+-- Portability :  non-portable (only on platforms that provide a regex lib)
+--
+-- $Id: Regex.hs,v 1.1 2001/08/02 11:20:50 simonmar Exp $
+--
+-- Regular expression matching.
+-- Uses the POSIX regular expression interface in Text.Regex.Posix for now.
+--
+-----------------------------------------------------------------------------
+
+module Text.Regex (
+    Regex,
+    mkRegex,
+    mkRegexWithOpts,
+    matchRegex,
+    matchRegexAll
+  ) where
+
+import Prelude
+import qualified Text.Regex.Posix as RE
+import System.IO.Unsafe
+
+type Regex = RE.Regex
+
+mkRegex :: String -> Regex
+mkRegex s = unsafePerformIO (RE.regcomp s RE.regExtended)
+
+mkRegexWithOpts :: String -> Bool -> Bool -> Regex
+mkRegexWithOpts s single_line case_sensitive
+   = unsafePerformIO (RE.regcomp s (RE.regExtended + newline + igcase))
+   where
+       newline | single_line = 0
+               | otherwise   = RE.regNewline
+
+       igcase  | case_sensitive = 0 
+               | otherwise      = RE.regIgnoreCase
+
+matchRegex :: Regex -> String -> Maybe [String]
+matchRegex p str = 
+  case (unsafePerformIO (RE.regexec p str)) of
+       Nothing -> Nothing
+       Just (before, match, after, sub_strs) -> Just sub_strs
+
+matchRegexAll :: Regex -> String ->
+        Maybe ( String,  -- $`
+                String,  -- $&
+                String,  -- $'
+                [String] -- $1..
+              )
+matchRegexAll p str = unsafePerformIO (RE.regexec p str)
+