{-# LANGUAGE FlexibleContexts, FlexibleInstances, UndecidableInstances, CPP #-} {-# OPTIONS -fno-warn-orphans #-} {-| Literal notation for regular expression. Importing this module with the 'QuasiQuotes' and 'OverloadedStrings' extensions making possible to directly specify reqular expression literal. This means that awkward backslashes are not necessary. You can copy a regular expression in other languages and paste it to your Haskell program. Sample code: > { -# LANGUAGE QuasiQuotes, OverloadedStrings #- } > -- Due to Haddock limitation, spaces are inserted after and before "}". > -- Remove them if you copy this. > > import Text.Regex.Literal > import Text.Regex.Posix > > -- Regular expression as the regular expression literal > regexp :: Regex > regexp = [$re|\\(foo)\\(bar\.c)|] > > -- Regular expression as the String literal > -- regexp :: Regex > -- regexp = makeRegex ("\\\\(foo)\\\\(bar\\.c)" :: String) GHC 6.12.3 or earlier requires the dollar sign before \"re\". GHC 7.0.1 does not allow the dollar sign before \"re\". GHC 7.0.2 or later allows the dollar sign before \"re\" as an obsoleted syntax. So, use GHC other than 7.0.1 and specify the dollor sign for portability. -} module Text.Regex.Literal (re) where import Data.String import Language.Haskell.TH import Language.Haskell.TH.Quote import Text.Regex.Base {-| A 'QuasiQuoter' function to implement regular expression literal. -} re :: QuasiQuoter #if __GLASGOW_HASKELL__ >= 700 re = QuasiQuoter parseExprExp parseExprPat parseExprType parseExprDec #else re = QuasiQuoter parseExprExp parseExprPat #endif parseExprExp :: String -> ExpQ parseExprExp x = return . LitE . StringL $ x parseExprPat :: String -> PatQ parseExprPat = undefined #if __GLASGOW_HASKELL__ >= 700 parseExprType :: String -> TypeQ parseExprType = undefined parseExprDec :: String -> Q [Dec] parseExprDec = undefined #endif instance (RegexMaker regex compOpt execOpt String) => IsString regex where fromString s = make s where make :: (RegexMaker regex compOpt execOpt String) => String -> regex make = makeRegex