wrap.hs

{-# LANGUAGE OverloadedStrings #-}

module Wrap where

import qualified Data.Text as T
import Prelude hiding (Word)
import Data.List


type LinePos = Int
type Word = T.Text

data StringFragment = StringFragment {t :: T.Text, i :: LinePos}

inputText :: T.Text
inputText = "Some text for me"

breakTextAt :: T.Text -> Int -> T.Text
breakTextAt text int = t result
  where result = foldl (\acc w -> f acc w) emptyFragment words
        words = T.words text
        emptyFragment = StringFragment "" 0
        f fragment word = concatFragment fragment word int

wordAtBreak :: Int -> Word -> LinePos -> Bool
wordAtBreak breakPos word pos = if endOfWordPos >= breakPos && (endOfWordPos `mod` breakPos) /= 0
                                then True
                                else False
  where endOfWordPos = pos + T.length word

concatFragment :: StringFragment -> Word -> Int -> StringFragment
concatFragment (StringFragment s pos) word breakPos
  | pos == 0 = StringFragment (s <> word) (T.length word)
  | otherwise = if breakCondition word pos
                then StringFragment lineBrokenWord (T.length word)
                else StringFragment normal (pos + T.length word + 1)
  where breakCondition = wordAtBreak breakPos
        lineBrokenWord = s <> "\n" <> word
        normal = s <> " " <> word

wrap.scala

class Wrapper {

  def wrap(s: String, colNum: Int): String = {
    val ss = s.split(" ")

    def nextWordIsAtBreak(word: String, curPos: Int): Boolean = {
      val posAtEndOfWord = curPos + word.length
      if (posAtEndOfWord > colNum && posAtEndOfWord % colNum != 0) true
      else false
    }


    val (wrappedString, _) = ss.foldLeft(("", 0))((acc, elem) => {
      val (accumulatedString, pos) = acc
      if (pos == 0) {
        (accumulatedString ++ elem, elem.length)
      } else {
        if (nextWordIsAtBreak(elem, pos)) {
          (accumulatedString ++ "\n" ++ elem, elem.length)
        } else {
          (accumulatedString ++ " " ++ elem, pos + elem.length + 1)
        }
      }
    }
    )
    wrappedString
  }
}