ignore Extension flag, suspend unpickling Monad

Author: bishabosha

src/compiler/scala/tools/nsc/tasty/TreeUnpickler.scala

@@ -796,7 +796,7 @@ abstract class TreeUnpickler(reader: TastyReader,
       val localCtx = localContext(sym)
       val noCycle  = tag match {
         case DEFDEF =>
-          assertTasty(!completer.tastyFlagSet, s"unsupported flags on def: ${completer.tastyFlagSet.show}")
+          assertTasty(!(completer.tastyFlagSet &~ Extension), s"unsupported flags on def: ${completer.tastyFlagSet.show}")
           val tparams = readParams[NoCycle](TYPEPARAM)(localCtx)
           val vparamss = readParamss(localCtx)
           val tpt = readTpt()(localCtx)

test/tasty/src-3/tastytest/Functor.scala

@@ -1,3 +1,3 @@
 package tastytest
 
-trait Functor[F[_]] { def map[A,B](fa: F[A])(f: A => B): F[B] }
+trait Functor[F[_]] { def (fa: F[A]) map[A,B](f: A => B): F[B] }

test/tasty/src-3/tastytest/FunctorI.scala

@@ -1,3 +1,3 @@
 package tastytest
 
-trait FunctorI[F[_ <: Int]] { def map[A <: Int, B <: Int](fa: F[A])(f: A => B): F[B] }
+trait FunctorI[F[_ <: Int]] { def (fa: F[A]) map[A <: Int, B <: Int](f: A => B): F[B] }

test/tasty/src-3/tastytest/FunctorL.scala

@@ -1,3 +1,3 @@
 package tastytest
 
-trait FunctorL[F[_] <: List[_]] { def map[A,B](fa: F[A])(f: A => B): F[B] }
+trait FunctorL[F[_] <: List[_]] { def (fa: F[A]) map[A,B](f: A => B): F[B] }

test/tasty/suspended/tastytest/Monad.scala

@@ -0,0 +1,7 @@
+package tastytest
+
+trait Monad[F[_]] extends Functor[F] {
+  def pure[A](x: A): F[A]
+  def (fa: F[A]) flatMap [A,B](f: A => F[B]): F[B]
+  def (fa: F[A]) map [A,B] (f: A => B) = flatMap(fa)(f `andThen` pure)
+}

test/tasty/suspended/tastytest/Reader.scala

@@ -0,0 +1,8 @@
+package tastytest
+
+trait Reader[Ctx] extends Monad[[X] =>> Ctx => X] {
+  def (r: Ctx => A) flatMap[A, B](f: A => Ctx => B): Ctx => B =
+    ctx => f(r(ctx))(ctx)
+  def pure[A](x: A): Ctx => A =
+    ctx => x
+}

test/tasty/suspended/tastytest/TestMonad.scala

@@ -0,0 +1,24 @@
+package tastytest
+
+object TestFunctor {
+
+  implicit object ListMonad extends Monad[List] {
+
+    def flatMap[A, B](fa: List[A])(f: A => List[B]): List[B] = fa.flatMap(f)
+    def pure[A](x: A): List[A] = x :: Nil
+
+    // error: Missing implementation for:
+    //   def map[A, B](fa: Monad.this.F[A])(f: A => B): Monad.this.F[B] // inherited from trait Functor
+    override def map[A, B](fa: List[A])(f: A => B): List[B] = fa.map(f)
+
+  }
+
+  def pureToString[F[_], A](fa: F[A])(implicit F: Monad[F]): F[String] = F.flatMap(fa)(a => F.pure(a.toString))
+
+  def test1 = assert(pureToString(List(1,2,3)) === List("1","2","3"))
+
+  def main(args: Array[String]): Unit = {
+    test1
+    println("Suite passed!")
+  }
+}