Text.Regex.Base

Classes and instances for Regex matching.

This module merely imports and re-exports the common part of the new api: Text.Regex.Base.RegexLike and Text.Regex.Base.Context.

To see what result types the instances of RegexContext can produce, please read the Text.Regex.Base.Context haddock documentation.

This does not provide any of the backends, just the common interface they all use. The modules which provide the backends and their cabal packages are:

• Text.Regex.Posix from regex-posix

• Text.Regex from regex-compat (uses regex-posix)

• Text.Regex.Parsec from regex-parsec

• Text.Regex.DFA from regex-dfa

• Text.Regex.PCRE from regex-pcre

• Test.Regex.TRE from regex-tre

In fact, just importing one of the backends is adequate, you do not also need to import this module.

Example

The code

import Text.Regex.Base
import Text.Regex.Posix ((=~),(=~~)) -- or TDFA or PCRE or ...

main = do
    print b
    print c
    print d
  where
    b :: Bool
    b = ("abaca" =~ "(.)a")
    c :: [MatchArray]
    c = ("abaca" =~ "(.)a")
    d :: Maybe (String,String,String,[String])
    d = ("abaca" =~~ "(.)a")

will output

True
[array (0,1) [(0,(1,2)),(1,(1,1))],array (0,1) [(0,(3,2)),(1,(3,1))]]
Just ("a","ba","ca",["b"])