package com.ciriscr.desafios

import scala.collection.mutable.ArrayBuffer

/**
 * Created with IntelliJ IDEA.
 * User: londo
 * Date: 23/07/12
 * Time: 08:24 PM
 */

//código fuente; https://bitbucket.org/londo/solveet-desafios
trait BrainfuckInterpreter {

  private val mem = ArrayBuffer.fill[Int](30000)(0)
  private var dp = 0

  def interpretar(in: Array[Char]) {
    var i = 0
    println()
    while (in.size > i) {
      in(i) match {
        case '>' => dp += 1
        case '<' => dp -= 1
        case '+' => mem(dp) += 1
        case '-' => mem(dp) -= 1
        case '.' => println(mem(dp))
//        case ',' =>
        case '[' => i = despues(in)(']', i)
        case ']' => i = anterior(in)('[', i)
        case f @ _ => throw new UnsupportedOperationException(f + " no soportado")
      }
      i += 1
    }
  }

  def anterior(in: Array[Char])(c: Char, i: Int): Int = {
    if (dp == 0 || in(i) == c) i
    else anterior(in)(c, i-1)
  }

  def despues(in: Array[Char])(c: Char, i: Int): Int = {
    if (dp == 0 || in(i) == c) i
    else despues(in)(c, i+1)
  }

}