33 lines
1.1 KiB
Haskell
33 lines
1.1 KiB
Haskell
module Justify
|
|
( makeParagraph
|
|
) where
|
|
import Data.Ratio
|
|
|
|
makeParagraph :: Int -> String -> [String]
|
|
makeParagraph maxl = map (justify maxl) . lineSplit maxl
|
|
|
|
justify :: Int -> ([String],Int,Int,Bool) -> String
|
|
justify maxl (ws,ccount,wcount,True) = concat $ interweave (reverse ws)
|
|
$ map f $ splitExtra (wcount-1) extrac
|
|
where
|
|
f n = replicate (n+1) ' '
|
|
extrac = maxl - (ccount + wcount - 1)
|
|
justify _ (ws,_,_,False) = unwords $ reverse ws
|
|
|
|
interweave :: [a] -> [a] -> [a]
|
|
interweave (x:xs) (y:ys) = x:y:interweave xs ys
|
|
interweave xs ys = xs ++ ys
|
|
|
|
splitExtra :: Int -> Int -> [Int]
|
|
splitExtra nword nchar = zipWith (-) flist (0:flist)
|
|
where
|
|
flist = map floor $ scanl1 (+) $ replicate nword (nchar % nword)
|
|
|
|
lineSplit :: Int -> String -> [([String],Int,Int,Bool)]
|
|
lineSplit maxl s = f ([],0,0,False) $ words s
|
|
where
|
|
f (curline,ccount,wcount,_) (wrd:wrds)
|
|
| ccount + wcount + length wrd > maxl = (curline,ccount,wcount,True) : f ([wrd],length wrd,1,False) wrds
|
|
| otherwise = f (wrd:curline, ccount + length wrd, wcount+1,False) wrds
|
|
f x [] = [x]
|