-----------------------------------------------------------------------------
-- |
-- Module      :  Util
-- Copyright   :  Copyright (c) 2007 Igor Boehm - Bytelabs.org. All rights reserved.
-- License     :  BSD-style (see the file LICENSE)
-- Author      :  Igor Boehm  <igor@bytelabs.org>
--
-- General utility functions.
-----------------------------------------------------------------------------

module Util (
   -- Functions
   stringToInt,
   stringToUpper,
   stringFoldr,
) where

{- unqualified imports  -}
import Data.Char

{- qualified imports  -}

------------------------------------------------------------------------------------

{- | stToInt. Convert a string to a number given a base. -}
stToInt :: Int -> String -> Int
stToInt base digits =
  sign * (foldl acc 0 $ concatMap digToInt digits1)
  where
    splitSign ('-' : ds) = ((-1), ds)
    splitSign ('+' : ds) = ( 1  , ds)
    splitSign ds         = ( 1  , ds)
    (sign, digits1)      = splitSign digits
    digToInt c  | c >= '0' && c <= '9'
                      = [ord c - ord '0']
                | c >= 'A' && c <= 'Z'
                      =  [ord c - ord 'A' + 10]
                | c >= 'a' && c <= 'z'
                      =  [ord c - ord 'a' + 10]
                | otherwise = []
    acc i1 i0 = i1 * base + i0

{- | stringToInt. Convert String to Int. -}
stringToInt :: String -> Int
stringToInt str = stToInt 10 str

{- | stringToUpper. -}
stringToUpper :: String -> String
stringToUpper str = map (toUpper) (str)

{- | stringFoldr. -}
stringFoldr :: (String -> String -> String) -> [String] -> String
stringFoldr f [] = ""
stringFoldr f xs = foldr1 f xs

------------------------------------------------------------------------------------