Merge pull request #2650 from paulp/issue/6221

SI-6221 inference with Function1 subtypes.

7 files changed, 74 insertions, 7 deletions

diff --git a/test/files/neg/names-defaults-neg.check b/test/files/neg/names-defaults-neg.check
index f6bd703e1f..cdc12c2490 100644
--- a/test/files/neg/names-defaults-neg.check
+++ b/test/files/neg/names-defaults-neg.check
@@ -125,9 +125,12 @@ names-defaults-neg.scala:134: error: missing parameter type for expanded functio
 names-defaults-neg.scala:135: error: parameter 'a' is already specified at parameter position 1
   val taf3 = testAnnFun(b = _: String, a = get(8))
                                          ^
-names-defaults-neg.scala:136: error: wrong number of parameters; expected = 2
+names-defaults-neg.scala:136: error: missing parameter type for expanded function ((x$3) => testAnnFun(x$3, ((x$4) => b = x$4)))
   val taf4: (Int, String) => Unit = testAnnFun(_, b = _)
-                                              ^
+                                               ^
+names-defaults-neg.scala:136: error: missing parameter type for expanded function ((x$4) => b = x$4)
+  val taf4: (Int, String) => Unit = testAnnFun(_, b = _)
+                                                      ^
 names-defaults-neg.scala:144: error: variable definition needs type because 'x' is used as a named argument in its body.
   def t3 { var x = t.f(x = 1) }
                ^
@@ -165,4 +168,4 @@ names-defaults-neg.scala:180: error: reference to x is ambiguous; it is both a m
   class u18 { var x: Int = u.f(x = 1) }
                                  ^
 four warnings found
-41 errors found
+42 errors found
diff --git a/test/files/neg/t1181.check b/test/files/neg/t1181.check
index 3724752a85..13b73d5381 100644
--- a/test/files/neg/t1181.check
+++ b/test/files/neg/t1181.check
@@ -1,8 +1,10 @@
 t1181.scala:8: warning: a pure expression does nothing in statement position; you may be omitting necessary parentheses
      case (Nil, Nil) => map
                         ^
-t1181.scala:9: error: missing parameter type
+t1181.scala:9: error: type mismatch;
+ found   : scala.collection.immutable.Map[Symbol,Symbol]
+ required: Symbol
      _ => buildMap(map.updated(keyList.head, valueList.head), keyList.tail, valueList.tail)
-     ^
+                  ^
 one warning found
 one error found
diff --git a/test/files/neg/t556.check b/test/files/neg/t556.check
index c278e13991..5135dc92ef 100644
--- a/test/files/neg/t556.check
+++ b/test/files/neg/t556.check
@@ -1,4 +1,4 @@
-t556.scala:3: error: wrong number of parameters; expected = 1
+t556.scala:3: error: missing parameter type
   def g:Int = f((x,y)=>x)
-                     ^
+                 ^
 one error found
diff --git a/test/files/pos/t6221.scala b/test/files/pos/t6221.scala
new file mode 100644
index 0000000000..dd7776f596
--- /dev/null
+++ b/test/files/pos/t6221.scala
@@ -0,0 +1,29 @@
+class MyFunc[-A, +B] extends (A => B) { def apply(x: A): B = ??? }
+
+class MyCollection[A] {
+  def map[B](f: MyFunc[A, B]): MyCollection[B] = new MyCollection[B]
+}
+
+class OtherFunc[-A, +B] {}
+
+object Test {
+  implicit def functionToMyFunc[A, B](f: A => B): MyFunc[A, B] = new MyFunc
+
+  implicit def otherFuncToMyFunc[A, B](f: OtherFunc[A, B]): MyFunc[A, B] = new MyFunc
+
+  def main(args: Array[String]) {
+    val col = new MyCollection[Int]
+
+    // Doesn't compile: error: missing parameter type for expanded function ((x$1) => x$1.toString)
+    println(col.map(_.toString))
+
+    // Doesn't compile: error: missing parameter type
+    println(col.map(x => x.toString))
+
+    // Does compile
+    println(col.map((x: Int) => x.toString))
+
+    // Does compile (even though type params of OtherFunc not given)
+    println(col.map(new OtherFunc))
+  }
+}
\ No newline at end of file
diff --git a/test/files/run/t6221.check b/test/files/run/t6221.check
new file mode 100644
index 0000000000..aa1bdd0e6e
--- /dev/null
+++ b/test/files/run/t6221.check
@@ -0,0 +1 @@
+((x) => x.$percent(2).$eq$eq(0))
diff --git a/test/files/run/t6221/Macros_1.scala b/test/files/run/t6221/Macros_1.scala
new file mode 100644
index 0000000000..c9500626d8
--- /dev/null
+++ b/test/files/run/t6221/Macros_1.scala
@@ -0,0 +1,22 @@
+import language.experimental.macros
+import language.implicitConversions
+import scala.reflect.macros.Context
+import scala.reflect.runtime.universe.Tree
+
+class ReflectiveClosure[A, B](val tree: Tree, fn: A => B) extends (A => B) {
+  def apply(x: A) = fn(x)
+}
+
+object ReflectiveClosure {
+  implicit def reflectClosure[A, B](f: A => B): ReflectiveClosure[A, B] = macro Macros.reflectiveClosureImpl[A, B]
+}
+
+object Macros {
+  def reflectiveClosureImpl[A, B](c: Context)(f: c.Expr[A => B]): c.Expr[ReflectiveClosure[A, B]] = {
+    import c.universe._
+    val u = treeBuild.mkRuntimeUniverseRef
+    val m = EmptyTree
+    val tree = c.Expr[scala.reflect.runtime.universe.Tree](Select(c.reifyTree(u, m, f.tree), newTermName("tree")))
+    c.universe.reify(new ReflectiveClosure(tree.splice, f.splice))
+  }
+}
diff --git a/test/files/run/t6221/Test_2.scala b/test/files/run/t6221/Test_2.scala
new file mode 100644
index 0000000000..9f6b2280a7
--- /dev/null
+++ b/test/files/run/t6221/Test_2.scala
@@ -0,0 +1,10 @@
+object Test extends App {
+  implicit class PimpedList[T](val list: List[T]) {
+    def query(predicate: ReflectiveClosure[T, Boolean]): List[T] = {
+      println(predicate.tree)
+      list filter predicate
+    }
+  }
+
+  List(1, 2, 3).query(x => x % 2 == 0)
+}
\ No newline at end of file