QuickCheck.scala

package quickcheck

import common._

import org.scalacheck._
import Arbitrary._
import Gen._
import Prop._

abstract class QuickCheckHeap extends Properties("Heap") with IntHeap {

  property("min1") = forAll { a: Int =>
    val h = insert(a, empty)
    findMin(h) == a
  }

  property("min of only 2 inserted elements") = forAll { (a: Int, b: Int) =>
    val h = insert(a, insert(b, empty))
    findMin(h) == (if (a < b) a else b)
  }

  property("delete the only element") = forAll { a: Int =>
    val h: H = insert(a, empty)
    isEmpty(deleteMin(h))
  }

  property("min of two heaps") = forAll { (h: H, g: H) =>
    val a = findMin(h)
    val b = findMin(g)
    findMin(meld(h, g)) == (if (a < b) a else b)
  }

  property("continually delete from a heap") = forAll { h: H =>

    def unpackHeap(heap: Heap, elems: List[Int]) : (Heap, List[Int]) = {
      heap match {
        case empty => elems
        case _ =>
      }
      ???
    }
    
    ???
  }


  lazy val genHeap: Gen[H] = for {
    l <- arbitrary[Int]
    m <- oneOf(const(empty), genHeap)
  } yield insert(l, m)


  lazy val genMap: Gen[Map[Int,Int]] = for {
    k <- arbitrary[Int]
    v <- arbitrary[Int]
    m <- oneOf(const(Map.empty[Int,Int]), genMap)
  } yield m.updated(k, v)


  implicit lazy val arbHeap: Arbitrary[H] = Arbitrary(genHeap)

}