Merge pull request #438 from Hydrotoast/master

Widen "oneOf" argument to "Iterable" from "Seq"

jvm/src/test/scala/org/scalacheck/GenSpecification.scala

@@ -58,6 +58,11 @@ object GenSpecification extends Properties("Gen") with GenSpecificationVersionSp
     forAll(frequency(List.fill(n)((1,const(0))): _*)) { _ == 0 }
   }
 
+  property("frequency 4") =
+    Prop.throws(classOf[IllegalArgumentException]) {
+      frequency()
+    }
+
   property("lzy") = forAll((g: Gen[Int]) => lzy(g) == g)
 
   property("wrap") = forAll((g: Gen[Int]) => delay(g) == g)
@@ -141,6 +146,13 @@ object GenSpecification extends Properties("Gen") with GenSpecificationVersionSp
     }
   }
 
+  property("oneOf n in set") = forAll { (s: Set[Int]) =>
+    Try(oneOf(s)) match {
+      case Success(g) => forAll(g)(s.contains)
+      case Failure(_) => Prop(s.isEmpty)
+    }
+  }
+
   property("oneOf 2") = forAll { (n1:Int, n2:Int) =>
     forAll(oneOf(n1, n2)) { n => n == n1 || n == n2 }
   }

src/main/scala/org/scalacheck/Gen.scala

@@ -521,15 +521,21 @@ object Gen extends GenArities with GenVersionSpecific {
   /** Creates a resized version of a generator */
   def resize[T](s: Int, g: Gen[T]) = gen((p, seed) => g.doApply(p.withSize(s), seed))
 
-  /** Picks a random value from a list */
-  def oneOf[T](xs: Seq[T]): Gen[T] =
+  /** Picks a random value from a list. */
+  def oneOf[T](xs: Iterable[T]): Gen[T] =
     if (xs.isEmpty) {
       throw new IllegalArgumentException("oneOf called on empty collection")
     } else {
       val vector = xs.toVector
       choose(0, vector.size - 1).map(vector(_))
     }
 
+  /** Picks a random value from a list.
+   *  @todo Remove this overloaded method in the next major release. See #438.
+   */
+  def oneOf[T](xs: Seq[T]): Gen[T] =
+    oneOf(xs: Iterable[T])
+
   /** Picks a random value from a list */
   def oneOf[T](t0: T, t1: T, tn: T*): Gen[T] = oneOf(t0 +: t1 +: tn)