Tibetan.hs

-- | Module to display positive integral values as strings
module TextShow.Data.Integral.Tibetan ( builderBo
                                      , showBo) where

import qualified Data.Text.Lazy as TL
import TextShow

-- | Display positive integer as a `String`
--
-- > λ > showBo 312
-- > Just "༣༡༢"
showBo :: Integer -> Maybe String
showBo = (fmap toString) . builderBo

-- | show a positive intgeger as text, return `Nothing` if that doesn't work
builderBo :: (Integral a) => a -> Maybe Builder
builderBo int
    | int >= 0  = Just . fromLazyText $ foldr (.) (id) 
        (zipWith TL.replace 
            (map showT [0..9])
            ["༠","༡","༢","༣","༤","༥","༦","༧","༨","༩"])
        (showT (fromIntegral int :: Integer))
    | otherwise = Nothing

showT = TL.pack . show