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

--

-- Util.hs, part of Alex

--

-- (c) Simon Marlow 2003

--

-- General utilities used in various parts of Alex

--

-- ----------------------------------------------------------------------------}

module Util

  ( str

  , char

  , nl

  , paren

  , brack

  , interleave_shows

  , space

  , cjustify

  , ljustify

  , rjustify

  , spaces

  , hline

  ) where

-- Pretty-printing utilities

str :: String -> String -> String

str = showString

char :: Char -> String -> String

char c = (c :)

nl :: String -> String

nl = char '\n'

paren :: (String -> String) -> String -> String

paren s = char '(' . s . char ')'

brack :: (String -> String) -> String -> String

brack s = char '[' . s . char ']'

interleave_shows :: (String -> String) -> [String -> String] -> String -> String

interleave_shows _ [] = id

interleave_shows s xs = foldr1 (\a b -> a . s . b) xs

space :: String -> String

space = char ' '

cjustify, ljustify, rjustify :: Int -> String -> String

cjustify n s = spaces halfm ++ s ++ spaces (m - halfm)

  where

    m     = n - length s

    halfm = m `div` 2

ljustify n s = s ++ spaces (max 0 (n - length s))

rjustify n s = spaces (n - length s) ++ s

spaces   :: Int -> String

spaces n = replicate n ' '

hline :: String

hline = replicate 77 '-'