wc.scala

import scalaz._
import Scalaz._

object CVersion {
  def wc(cs: TraversableOnce[Char]): (Int,Int,Int) = {
    var numLines,numWords,numChars = 0
    var inWord = false

    cs.foreach { char =>
      numChars += 1

      if (char == '\n') numLines += 1

      if (char == ' ' || char == '\n' || char == '\t') {
        inWord = false
      } else if (inWord == false) {
        inWord = true
        numWords += 1
      }
    }

    (numChars, numWords, numLines)
  }
}

object FunctionalVersion {
  def test(b: Boolean): Int = if (b) 1 else 0

  def wc(cs: TraversableOnce[Char]): (Int,Int,Int) = {
    def countChars(c: Char): Writer[Int,Char] = c.set(1)

    def countLines(c: Char): Writer[Int,Char] = c.set(test(c == '\n'))

    def countWord(c: Char): State[(Int,Boolean),Char] = for {
      tuple <- get[(Int,Boolean)]
      (n,inWord) = tuple
      notBlank = !( c == ' ' || c == '\n' || c == '\t')
      _ <- put(n + test(!inWord && notBlank),notBlank)
    } yield c

    val csList = cs.toList
    val chars: Int = csList.map(countChars).sequenceU.run._1
    val lines: Int = csList.map(countLines).sequenceU.run._1
    val words: Int = csList.map(countWord).sequenceU.exec((0,false))._1

    (chars,words,lines)
  }
}

object TestStrings {
  val testString = """Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim
veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea
commodo consequat. Duis aute irure dolor in reprehenderit in voluptate
velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat
cupidatat non proident, sunt in culpa qui officia deserunt mollit anim
id est laborum.
"""
}

object Main extends App {
  import TestStrings._
  println(CVersion.wc(testString))
  println(FunctionalVersion.wc(testString))
}