Single Abstract Method support: synthesize SAMs

Under `-Xexperimental`, `typedFunction` invokes `synthesizeSAMFunction`
when the expected type for the function literal (`pt`) is not the built-in
`FunctionN` type of the expected arity, but `pt` does have a SAM
with the expected number of arguments.

PS: We'll require `import language.sam` instead of `-Xexperimental`,
as soon as the SIP is ready and there are more tests.

1 files changed, 6 insertions, 2 deletions

diff --git a/test/files/pos/t6221.scala b/test/files/pos/t6221.scala
index dd7776f596..34f02859f3 100644
--- a/test/files/pos/t6221.scala
+++ b/test/files/pos/t6221.scala
@@ -7,23 +7,27 @@ class MyCollection[A] {
 class OtherFunc[-A, +B] {}
 
 object Test {
-  implicit def functionToMyFunc[A, B](f: A => B): MyFunc[A, B] = new MyFunc
+  implicit def functionToMyFunc[A, B](f: A => B): MyFunc[A, B] = new MyFunc // = new MyFunc[A,Nothing]();
 
-  implicit def otherFuncToMyFunc[A, B](f: OtherFunc[A, B]): MyFunc[A, B] = new MyFunc
+  implicit def otherFuncToMyFunc[A, B](f: OtherFunc[A, B]): MyFunc[A, B] = new MyFunc // = new MyFunc[A,Nothing]();
 
   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))
+    // scala.this.Predef.println(col.map[String](Test.this.functionToMyFunc[Int, String](((x$1: Int) => x$1.toString()))));
 
     // Doesn't compile: error: missing parameter type
     println(col.map(x => x.toString))
+    // scala.this.Predef.println(col.map[String](Test.this.functionToMyFunc[Int, String](((x: Int) => x.toString()))));
 
     // Does compile
     println(col.map((x: Int) => x.toString))
+    // scala.this.Predef.println(col.map[String](Test.this.functionToMyFunc[Int, String](((x: Int) => x.toString()))));
 
     // Does compile (even though type params of OtherFunc not given)
     println(col.map(new OtherFunc))
+    // scala.this.Predef.println(col.map[Nothing](Test.this.otherFuncToMyFunc[Any, Nothing](new OtherFunc[Any,Nothing]())))
   }
 }
\ No newline at end of file