Levenshtein.hs

--
-- Copyright (c) 2013 Bonelli Nicola <bonelli@antifork.org>
--
-- This program is free software; you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation; either version 2 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program; if not, write to the Free Software
-- Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
--

module CGrep.Strategy.Levenshtein (search) where

import qualified Data.ByteString.Char8 as C

import Control.Monad.Trans.Reader
import Control.Monad.IO.Class

import CGrep.Filter
import CGrep.Lang
import CGrep.Common
import CGrep.Output
import CGrep.Distance
import CGrep.Token

import Options
import Debug


search :: FilePath -> [Text8] -> ReaderT Options IO [Output]
search f patterns = do

    opt <- ask
    text <- liftIO $ getTargetContents f

    let filename = getTargetName f

    -- transform text

    let [text''', _ , _ , _] = scanr ($) text [ expandMultiline opt
                                              , contextFilter (getFileLang opt filename) (mkContextFilter opt)
                                              , ignoreCase opt
                                              ]

    -- parse source code, get the Cpp.Token list...

        tokens' = tokenizer text'''

    -- filter tokens...

        patterns' = map C.unpack patterns

        matches  = filter (\t -> any (\p -> p ~== snd t) patterns') tokens'

    putStrLevel1 $ "strategy  : running edit-distance (Levenshtein) search on " ++ filename ++ "..."
    putStrLevel2 $ "tokens    : " ++ show tokens'
    putStrLevel2 $ "matches   : " ++ show matches
    putStrLevel3 $ "---\n" ++ C.unpack text''' ++ "\n---"

    mkOutput filename text text''' matches