{- numbers for humans
 -
 - Copyright 2012-2013 Joey Hess <joey@kitenet.net>
 -
 - Licensed under the GNU GPL version 3 or higher.
 -}

module Utility.HumanNumber where

{- Displays a fractional value as a string with a limited number
 - of decimal digits. -}
showImprecise :: RealFrac a => Int -> a -> String
showImprecise precision n
	| precision == 0 || remainder == 0 = show (round n :: Integer)
	| otherwise = show int ++ "." ++ striptrailing0s (pad0s $ show remainder)
  where
	int :: Integer
	(int, frac) = properFraction n
	remainder = round (frac * 10 ^ precision) :: Integer
	pad0s s = (take (precision - length s) (repeat '0')) ++ s
	striptrailing0s = reverse . dropWhile (== '0') . reverse