-----------------------------------------------------------------------------
-- 
-- Module      :  HCube.Common
-- Copyright   :  (c) Todd Wegner 2012
-- License     :  BSD-style (see the LICENSE file)
-- 
-- Maintainer  :  echbar137@yahoo.co.in
-- Stability   :  provisional
-- Portability :  portable
--
-- Common utility functions that should not be exported. 
-----------------------------------------------------------------------------
{-# LANGUAGE Safe #-}
{-# OPTIONS_HADDOCK hide #-}

module HCube.Common where

import Control.Monad (liftM)
import Data.List
import HCube.Data

getLine2	= liftM reverse $ f "" where
    f rd	= getChar >>= g where
        g '\n'	= return rd
        g '\b'	= putStr " \b" >> if null rd then f "" else f $ tail rd
	g ch	= f (ch:rd)

-- Pretty prints two columns per screen.
twoPagesOnOne		:: String -> [String] -> [String]
twoPagesOnOne sp tx	= f $ splitAt (length tx `div` 2) tx where
    f (l1, l2)		= g l1 l2
    g (x:xs) (y:ys)	= concat [x, sp, y] : g xs ys
    g [] []		= []
    g xs []		= xs
    g [] xs		= xs

-- Pretty prints four columns per screen.
fourPagesOnOne		:: String -> [String] -> [String]
fourPagesOnOne sp 	= twoPagesOnOne sp . twoPagesOnOne sp

-- Pads spaces on the right.
padR				:: Int -> String -> String
padR ln chs			= chs ++ (replicate f ' ') where
    f				= ln - length chs 

-- Pads spaces on the left.
padL				:: Int -> String -> String
padL ln chs			= (replicate f ' ') ++ chs where
    f				= ln - length chs 

prShow			:: Show a => Int -> a -> String
prShow nm		= padR nm . show

plShow			:: Show a => Int -> a -> String
plShow nm		= padL nm . show