-- COMP1100 S1, 2006

-- Lab week 4 solution

import Data.Char

stringToUpper :: String -> String
stringToUpper []       = []
stringToUpper (ch:chs) = toUpper ch : stringToUpper chs

-- Alternatively, using map, which I may have talked about in lectures
-- by now:

stringToUpper' :: String -> String
stringToUpper' chs = map toUpper chs

-- or, in "point-free" style:
-- stringToUpper' :: String -> String
-- stringToUpper' = map toUpper