Quackers.hs

{- copyright (c) sreservoir.
   license bsd three-clause. -}

{-# LANGUAGE FlexibleInstances,TypeSynonymInstances #-}

module Text.Regex.Less.Quackers (QLR(..)) where

import qualified Text.Regex.PCRE.Light as R
import qualified Data.ByteString.Char8 as B
import Text.Regex.Less.REOpts

-- the QLR (QuacksLikeRegex) class:
  -- compile
  -- runopts
-- instances of QLR:
  -- String
  -- (String,[RECtOpts])
  -- (String,[RERtOpts])
  -- (String,([RECtOpts],[RERtOpts]))
  -- (String,([RERtOpts],[RECtOpts]))
  -- ((String,[RECtOpts]),[RERtOpts])
  -- ((String,[RERtOpts]),[RECtOpts])

-- QuacksLikeRegex: can =~ .
class QLR a where
  compile :: a -> R.Regex
  runopts :: a -> [R.PCREExecOption]

-- standard string.
instance QLR String where
  compile a = R.compile (B.pack a) []
  runopts _ = []

-- re << compile
instance QLR (String,[RECtOpt]) where
  compile (a,b) = R.compile (B.pack a) (reCtOpts b)
  runopts (_,_) = []

-- re << runtime
instance QLR (String,[RERtOpt]) where
  compile (a,_) = R.compile (B.pack a) []
  runopts (_,b) = reRtOpts b

-- re << compile << runtime
instance QLR (String,([RECtOpt],[RERtOpt])) where
  compile (a,(b,_)) = R.compile (B.pack a) (reCtOpts b)
  runopts (_,(_,c)) = reRtOpts c

-- re << runtime << compile
instance QLR (String,([RERtOpt],[RECtOpt])) where
  compile (a,(_,b)) = R.compile (B.pack a) (reCtOpts b)
  runopts (_,(c,_)) = reRtOpts c

-- (re << compile) << runtime
instance QLR ((String,[RECtOpt]),[RERtOpt]) where
  compile ((a,b),_) = R.compile (B.pack a) (reCtOpts b)
  runopts ((_,_),c) = reRtOpts c

-- (re << runtime) << compile
instance QLR ((String,[RERtOpt]),[RECtOpt]) where
  compile ((a,_),b) = R.compile (B.pack a) (reCtOpts b)
  runopts ((_,c),_) = reRtOpts c