#! /usr/bin/mira -exec
main :: [sys_message]
main = [Stdout (align (alignment algm) '$' (read file))]
       where [cmd, file, algm] = $*

alignment :: [char]->num->[char]->[char]
alignment "left"   = ljustify
alignment "center" = cjustify
alignment "right"  = rjustify
alignment x        = error "Alignment must be left, center, or right"

align :: (num->[char]->[char])->char->[char]->[char]
align just sep text = (lay . map (alignline just sep cols) . lines) text
                      where cols = colwidths sep text

split :: *->[*]->[[*]]
split sep = s []
            where s acc []     = [acc]
                  s acc (a:as) = acc:s [] as, if a==sep
                               = s (acc++[a]) as, otherwise

colwidths :: char->[char]->[num]
colwidths sep text = (map max . transpose . map (extend maxwidth 0)) widths
                     where widths = map (map (#) . split sep) (lines text)
                           maxwidth = max (map (#) widths)

alignline :: (num->[char]->[char])->char->[num]->[char]->[char]
alignline just sep cols = concat . map (++" ") . zipwith just cols . split sep

zipwith :: (*->**->***)->[*]->[**]->[***]
zipwith f xs ys = map f' (zip2 xs ys) where f' (x,y) = f x y

extend :: num->*->[*]->[*]
extend n k ls = ls ++ take (n-#ls) (repeat k)