Fix semantics of by-name application

 - If we lift one arg, we must lift them all.
   This preserves evaluation order.
 - But, never lift an by-name arg

Addresses the first half of #33.

1 files changed, 22 insertions, 0 deletions

diff --git a/src/test/scala/scala/async/run/anf/AnfTransformSpec.scala b/src/test/scala/scala/async/run/anf/AnfTransformSpec.scala
index 6dd4db7..595fa6c 100644
--- a/src/test/scala/scala/async/run/anf/AnfTransformSpec.scala
+++ b/src/test/scala/scala/async/run/anf/AnfTransformSpec.scala
@@ -205,4 +205,26 @@ class AnfTransformSpec {
     }
     result mustBe (true)
   }
+
+  @Test
+  def byNameExpressionsArentLifted() {
+    import _root_.scala.async.AsyncId.{async, await}
+    def foo(ignored: => Any, b: Int) = b
+    val result = async {
+      foo(???, await(1))
+    }
+    result mustBe (1)
+  }
+
+  @Test
+  def evaluationOrderRespected() {
+    import scala.async.AsyncId.{async, await}
+    def foo(a: Int, b: Int) = (a, b)
+    val result = async {
+      var i = 0
+      def next() = {i += 1; i}
+      foo(next(), await(next()))
+    }
+    result mustBe ((1, 2))
+  }
 }