scala-play solution to scala-coding dojo 18-10-2012

Application.scala

package controllers

import play.api._
import play.api.mvc._

object Application extends Controller {
  def is_cube(a: Int): Boolean = {
    (1 to (a / 2)).exists(x => x * x * x == a)
  }

  def is_square(a: Int): Boolean = {
    (1 to (a / 2)).exists(x => x * x == a)
  }
  
  def extract_square_and_cube(xs: List[Int]): String = {
    xs.filter(x => (is_square(x) && is_cube(x))).headOption.mkString
  }

  def number_list_to_ints(xs: String): List[Int] = {
    xs.split(", ").toList map (_.toInt)
  }

  // implicit parameter, something magically passed
  def index = Action { request =>
    val plus_reg = """.*?(\d+) plus (\d+)""".r
    val largest = """.*?largest: (\d+.*)""".r
    val mult = """.*?(\d+) multiplied by (\d+)""".r
    val sq_cube = """.*?square and a cube: (\d+.*)""".r

    val resp = request.queryString.get("q") map {
      seq => seq.head match {
        case plus_reg(a, b) => a.toInt + b.toInt
        case largest(numbers) => number_list_to_ints(numbers).max
        case mult(a, b) => a.toInt * b.toInt
        case sq_cube(numbers) => extract_square_and_cube(number_list_to_ints(numbers))
        case _ => Logger.info("Not handled thing" + request.queryString.get("q")); 0
      }
    }
    Logger.info("Query " + request.queryString.get("q") + "\tResponse " + resp.get)
    Ok("" + resp.get)
  }
}