implementation module StringUtils

import StdEnv

strlen :: String -> Int
strlen s = length s`
where
    s` :: [Char]
    s` = fromString s

pad_right :: String Int -> String
pad_right s l
| strlen s >= l = s
| otherwise = s +++ toString (repeatn (l - strlen s) ' ')

pad_left :: String Int -> String
pad_left s l
| strlen s >= l = s
| otherwise = toString (repeatn (l - strlen s) ' ') +++ s

join :: String [String] -> String
join glue [] = ""
join glue [s] = s
join glue [s:ss] = s +++ glue +++ join glue ss