New tests

Author: odersky

tests/neg-custom-args/captures/closure-avoidance.scala

@@ -0,0 +1,30 @@
+trait A
+trait B
+
+def test =
+  val f = (a: A^) =>
+    val b: B^ = ???
+    b
+
+  val f1: A^ => B^ = (a: A^) => // error -- can we make this work as for f2?
+    val b: B^ = ???
+    b
+
+  val f2: (x: A^) => B^ = (a: A^) =>
+    val b: B^ = ???
+    b   // ok
+
+  val g = (a: A^) =>
+    println("")
+    (??? : B^)
+
+  val test = g
+
+  val g1: A^ => B^ = (a: A^) => // error -- can we make this work as for g2?
+    println("")
+    (??? : B^)
+
+  val g2: (x: A^) => B^ = (a: A^) =>
+    println("")
+    (??? : B^) // ok
+

tests/pos-custom-args/captures/flatmapInPlace.scala

@@ -0,0 +1,19 @@
+trait Buffer[A]:
+
+  def apply(i: Int): A = ???
+
+  def flatMapInPlace(f: A => IterableOnce[A]^): this.type = {
+    val g = f
+    val s = 10
+     // capture checking: we need the copy since we box/unbox on g* on the next line
+      // TODO: This looks fishy, need to investigate
+      // Alternative would be to mark `f` as @use. It's not inferred
+      // since `^ appears in a function result, not under a box.
+    val newElems = new Array[(IterableOnce[A]^{f})](s)
+    var i = 0
+    while i < s do
+      val x = g(this(i))
+      newElems(i) = x
+      i += 1
+    this
+  }

tests/pos-custom-args/captures/leveltest.scala

@@ -0,0 +1,24 @@
+class Cap extends caps.ExclusiveCapability
+
+class A
+
+def T =
+  def test(x: A^): A^{x} = ???
+
+  def foo(): A^ = ???
+
+  val a: A^ = ???
+
+  val x = test(foo())
+  val _: A^ = x
+
+  val y = test(a) :: Nil
+  val _: List[A^{a}] = y
+
+  def z =
+    val b = test(a)
+    Nil.::(b)
+  val _: List[A^{a}] = z
+
+
+