{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE ViewPatterns #-}
{-# OPTIONS_GHC -fno-warn-tabs #-}
{-# OPTIONS_GHC -fno-warn-orphans #-}
module Hcompta.Lib.Data.Text where

import Data.Char (Char)
import Data.Eq (Eq(..))
import qualified Data.List as List
import Data.Maybe (Maybe(..))
import Data.String (String)
import Data.Text (Text)
import qualified Data.Text as Text

-- * Class 'SplitOnChar'

class SplitOnChar t where
	splitOnChar :: Char -> t -> [t]
instance SplitOnChar Text where
	splitOnChar sep t =
		case Text.uncons t of
		 Nothing -> []
		 Just (x, xs) ->
			if x == sep
			then splitOnChar sep xs
			else
				let (chunk, rest) = Text.break (== sep) t in
				chunk:splitOnChar sep rest
instance SplitOnChar String where
	splitOnChar sep t =
		case t of
		 [] -> []
		 x:xs ->
			if x == sep
			then splitOnChar sep xs
			else
				let (chunk, rest) = List.break (== sep) t in
				chunk:splitOnChar sep rest

-- * Class 'SplitOnCharWithEmpty'

class SplitOnCharWithEmpty t where
	splitOnCharWithEmpty :: Char -> t -> [t]
instance SplitOnCharWithEmpty Text where
	splitOnCharWithEmpty sep t =
		case Text.break (== sep) t of
		 (chunk, Text.uncons -> Just (_, rest)) -> chunk : splitOnCharWithEmpty sep rest
		 (chunk, _) -> [chunk]
instance SplitOnCharWithEmpty String where
	splitOnCharWithEmpty sep t =
		case List.break (== sep) t of
		 (chunk, _:rest) -> chunk : splitOnCharWithEmpty sep rest
		 (chunk, []) -> [chunk]