Types.hs

{- This file is part of razom-text-util.
 -
 - Written in 2015 by fr33domlover <fr33domlover@rel4tion.org>.
 -
 - ♡ Copying is an act of love. Please copy, reuse and share.
 -
 - The author(s) have dedicated all copyright and related and neighboring
 - rights to this software to the public domain worldwide. This software is
 - distributed without any warranty.
 -
 - You should have received a copy of the CC0 Public Domain Dedication along
 - with this software. If not, see
 - <http://creativecommons.org/publicdomain/zero/1.0/>.
 -}

module Text.Razom.Types
    ( Regex
    , PosRegex
    , LexError (..)
    , LexResult (..)
    )
where

import Data.Position (Position, PosRE)
import Text.Regex.Applicative (RE)

-- | A regular expression over Unicode characters.
type Regex a = RE Char a

-- | A position-aware regular expression over Unicode characters.
type PosRegex a = PosRE Char a

-- | An error returned when applying a regex fails. Parameters:
--
-- (1) Location of the error
-- (2) Previous tokens parsed successfully
-- (3) The rest of the text
data LexError t = LexError Position [t] String deriving Show

-- | What is returned by lexical analyzer.
type LexResult t = Either (LexError t) [t]