Merge pull request #1469 from dotty-staging/fix-scala.Dynamic

Fixes for scala.Dynamic

5 files changed, 73 insertions, 60 deletions

diff --git a/src/dotty/tools/dotc/ast/TreeInfo.scala b/src/dotty/tools/dotc/ast/TreeInfo.scala
index a48651ebf..7c3f7f385 100644
--- a/src/dotty/tools/dotc/ast/TreeInfo.scala
+++ b/src/dotty/tools/dotc/ast/TreeInfo.scala
@@ -630,20 +630,6 @@ object TreeInfo {
     }
   }
 
-  def isApplyDynamicName(name: Name) = (name == nme.updateDynamic) || (name == nme.selectDynamic) || (name == nme.applyDynamic) || (name == nme.applyDynamicNamed)
-
-  class DynamicApplicationExtractor(nameTest: Name => Boolean) {
-    def unapply(tree: Tree) = tree match {
-      case Apply(TypeApply(Select(qual, oper), _), List(Literal(Constant(name)))) if nameTest(oper) => Some((qual, name))
-      case Apply(Select(qual, oper), List(Literal(Constant(name)))) if nameTest(oper) => Some((qual, name))
-      case Apply(Ident(oper), List(Literal(Constant(name)))) if nameTest(oper) => Some((EmptyTree(), name))
-      case _ => None
-    }
-  }
-  object DynamicUpdate extends DynamicApplicationExtractor(_ == nme.updateDynamic)
-  object DynamicApplication extends DynamicApplicationExtractor(isApplyDynamicName)
-  object DynamicApplicationNamed extends DynamicApplicationExtractor(_ == nme.applyDynamicNamed)
-
   object MacroImplReference {
     private def refPart(tree: Tree): Tree = tree match {
       case TypeApply(fun, _) => refPart(fun)
diff --git a/src/dotty/tools/dotc/typer/Applications.scala b/src/dotty/tools/dotc/typer/Applications.scala
index 1fff14cc6..a9212e5d6 100644
--- a/src/dotty/tools/dotc/typer/Applications.scala
+++ b/src/dotty/tools/dotc/typer/Applications.scala
@@ -591,13 +591,7 @@ trait Applications extends Compatibility { self: Typer with Dynamic =>
 
       fun1.tpe match {
         case ErrorType => tree.withType(ErrorType)
-        case TryDynamicCallType =>
-          tree match {
-            case tree @ Apply(Select(qual, name), args) if !isDynamicMethod(name) =>
-              typedDynamicApply(qual, name, args, pt)(tree)
-            case _ =>
-              handleUnexpectedFunType(tree, fun1)
-          }
+        case TryDynamicCallType => typedDynamicApply(tree, pt)
         case _ =>
           tryEither {
             implicit ctx => simpleApply(fun1, proto)
@@ -679,7 +673,12 @@ trait Applications extends Compatibility { self: Typer with Dynamic =>
           }
       case _ =>
     }
-    assignType(cpy.TypeApply(tree)(typedFn, typedArgs), typedFn, typedArgs)
+    def tryDynamicTypeApply(): Tree = typedFn match {
+      case typedFn: Select if !pt.isInstanceOf[FunProto] => typedDynamicSelect(typedFn, typedArgs, pt)
+      case _                                             => tree.withType(TryDynamicCallType)
+    }
+    if (typedFn.tpe eq TryDynamicCallType) tryDynamicTypeApply()
+    else assignType(cpy.TypeApply(tree)(typedFn, typedArgs), typedFn, typedArgs)
   }
 
   /** Rewrite `new Array[T](....)` if T is an unbounded generic to calls to newGenericArray.
diff --git a/src/dotty/tools/dotc/typer/Dynamic.scala b/src/dotty/tools/dotc/typer/Dynamic.scala
index aeb3cca8c..b5ace87d3 100644
--- a/src/dotty/tools/dotc/typer/Dynamic.scala
+++ b/src/dotty/tools/dotc/typer/Dynamic.scala
@@ -2,15 +2,14 @@ package dotty.tools
 package dotc
 package typer
 
-import dotty.tools.dotc.ast.Trees.NamedArg
-import dotty.tools.dotc.ast.tpd._
+import dotty.tools.dotc.ast.Trees._
+import dotty.tools.dotc.ast.tpd
 import dotty.tools.dotc.ast.untpd
 import dotty.tools.dotc.core.Constants.Constant
 import dotty.tools.dotc.core.Contexts.Context
 import dotty.tools.dotc.core.Names.Name
 import dotty.tools.dotc.core.StdNames._
 import dotty.tools.dotc.core.Types._
-import dotty.tools.dotc.core.Mode
 import dotty.tools.dotc.core.Decorators._
 
 object Dynamic {
@@ -28,44 +27,78 @@ object Dynamic {
  *  The first matching rule of is applied.
  */
 trait Dynamic { self: Typer with Applications =>
+  import Dynamic._
+  import tpd._
 
   /** Translate selection that does not typecheck according to the normal rules into a applyDynamic/applyDynamicNamed.
-   *    foo.bar(baz0, baz1, ...)              ~~> foo.applyDynamic(bar)(baz0, baz1, ...)
-   *    foo.bar(x = bazX, y = bazY, baz, ...) ~~> foo.applyDynamicNamed("bar")(("x", bazX), ("y", bazY), ("", baz), ...)
+   *    foo.bar(baz0, baz1, ...)                       ~~> foo.applyDynamic(bar)(baz0, baz1, ...)
+   *    foo.bar[T0, ...](baz0, baz1, ...)              ~~> foo.applyDynamic[T0, ...](bar)(baz0, baz1, ...)
+   *    foo.bar(x = bazX, y = bazY, baz, ...)          ~~> foo.applyDynamicNamed("bar")(("x", bazX), ("y", bazY), ("", baz), ...)
+   *    foo.bar[T0, ...](x = bazX, y = bazY, baz, ...) ~~> foo.applyDynamicNamed[T0, ...]("bar")(("x", bazX), ("y", bazY), ("", baz), ...)
    */
-  def typedDynamicApply(qual: untpd.Tree, name: Name, args: List[untpd.Tree], pt: Type)(original: untpd.Apply)(
-      implicit ctx: Context): Tree = {
-    def isNamedArg(arg: untpd.Tree): Boolean = arg match { case NamedArg(_, _) => true; case _ => false }
-    val dynName = if (args.exists(isNamedArg)) nme.applyDynamicNamed else nme.applyDynamic
-    if (dynName == nme.applyDynamicNamed && untpd.isWildcardStarArgList(args)) {
-      ctx.error("applyDynamicNamed does not support passing a vararg parameter", original.pos)
-      original.withType(ErrorType)
-    } else {
-      def namedArgTuple(name: String, arg: untpd.Tree) = untpd.Tuple(List(Literal(Constant(name)), arg))
-      def namedArgs = args.map {
-        case NamedArg(argName, arg) => namedArgTuple(argName.toString, arg)
-        case arg => namedArgTuple("", arg)
+  def typedDynamicApply(tree: untpd.Apply, pt: Type)(implicit ctx: Context): Tree = {
+    def typedDynamicApply(qual: untpd.Tree, name: Name, targs: List[untpd.Tree]): Tree = {
+      def isNamedArg(arg: untpd.Tree): Boolean = arg match { case NamedArg(_, _) => true; case _ => false }
+      val args = tree.args
+      val dynName = if (args.exists(isNamedArg)) nme.applyDynamicNamed else nme.applyDynamic
+      if (dynName == nme.applyDynamicNamed && untpd.isWildcardStarArgList(args)) {
+        ctx.error("applyDynamicNamed does not support passing a vararg parameter", tree.pos)
+        tree.withType(ErrorType)
+      } else {
+        def namedArgTuple(name: String, arg: untpd.Tree) = untpd.Tuple(List(Literal(Constant(name)), arg))
+        def namedArgs = args.map {
+          case NamedArg(argName, arg) => namedArgTuple(argName.toString, arg)
+          case arg => namedArgTuple("", arg)
+        }
+        val args1 = if (dynName == nme.applyDynamic) args else namedArgs
+        typedApply(untpd.Apply(coreDynamic(qual, dynName, name, targs), args1), pt)
       }
-      val args1 = if (dynName == nme.applyDynamic) args else namedArgs
-      typedApply(untpd.Apply(coreDynamic(qual, dynName, name), args1), pt)
+    }
+
+     tree.fun match {
+      case Select(qual, name) if !isDynamicMethod(name) =>
+        typedDynamicApply(qual, name, Nil)
+      case TypeApply(Select(qual, name), targs) if !isDynamicMethod(name) =>
+        typedDynamicApply(qual, name, targs)
+      case TypeApply(fun, targs) =>
+        typedDynamicApply(fun, nme.apply, targs)
+      case fun =>
+        typedDynamicApply(fun, nme.apply, Nil)
     }
   }
 
   /** Translate selection that does not typecheck according to the normal rules into a selectDynamic.
-   *    foo.bar ~~> foo.selectDynamic(bar)
+   *    foo.bar          ~~> foo.selectDynamic(bar)
+   *    foo.bar[T0, ...] ~~> foo.selectDynamic[T0, ...](bar)
    *
    *  Note: inner part of translation foo.bar(baz) = quux ~~> foo.selectDynamic(bar).update(baz, quux) is achieved
    *  through an existing transformation of in typedAssign [foo.bar(baz) = quux ~~> foo.bar.update(baz, quux)].
    */
-  def typedDynamicSelect(tree: untpd.Select, pt: Type)(implicit ctx: Context): Tree =
-    typedApply(coreDynamic(tree.qualifier, nme.selectDynamic, tree.name), pt)
+  def typedDynamicSelect(tree: untpd.Select, targs: List[Tree], pt: Type)(implicit ctx: Context): Tree =
+    typedApply(coreDynamic(tree.qualifier, nme.selectDynamic, tree.name, targs), pt)
 
   /** Translate selection that does not typecheck according to the normal rules into a updateDynamic.
    *    foo.bar = baz ~~> foo.updateDynamic(bar)(baz)
    */
-  def typedDynamicAssign(qual: untpd.Tree, name: Name, rhs: untpd.Tree, pt: Type)(implicit ctx: Context): Tree =
-    typedApply(untpd.Apply(coreDynamic(qual, nme.updateDynamic, name), rhs), pt)
+  def typedDynamicAssign(tree: untpd.Assign, pt: Type)(implicit ctx: Context): Tree = {
+    def typedDynamicAssign(qual: untpd.Tree, name: Name, targs: List[untpd.Tree]): Tree =
+      typedApply(untpd.Apply(coreDynamic(qual, nme.updateDynamic, name, targs), tree.rhs), pt)
+    tree.lhs match {
+      case Select(qual, name) if !isDynamicMethod(name) =>
+        typedDynamicAssign(qual, name, Nil)
+      case TypeApply(Select(qual, name), targs) if !isDynamicMethod(name) =>
+        typedDynamicAssign(qual, name, targs)
+      case _ =>
+        ctx.error("reassignment to val", tree.pos)
+        tree.withType(ErrorType)
+    }
+  }
 
-  private def coreDynamic(qual: untpd.Tree, dynName: Name, name: Name)(implicit ctx: Context): untpd.Apply =
-    untpd.Apply(untpd.Select(qual, dynName), Literal(Constant(name.toString)))
+  private def coreDynamic(qual: untpd.Tree, dynName: Name, name: Name, targs: List[untpd.Tree])(implicit ctx: Context): untpd.Apply = {
+    val select = untpd.Select(qual, dynName)
+    val selectWithTypes =
+      if (targs.isEmpty) select
+      else untpd.TypeApply(select, targs)
+    untpd.Apply(selectWithTypes, Literal(Constant(name.toString)))
+  }
 }
diff --git a/src/dotty/tools/dotc/typer/TypeAssigner.scala b/src/dotty/tools/dotc/typer/TypeAssigner.scala
index 36404a68f..6023bfcd0 100644
--- a/src/dotty/tools/dotc/typer/TypeAssigner.scala
+++ b/src/dotty/tools/dotc/typer/TypeAssigner.scala
@@ -168,7 +168,9 @@ trait TypeAssigner {
           val d2 = pre.nonPrivateMember(name)
           if (reallyExists(d2) && firstTry)
             test(tpe.shadowed.withDenot(d2), false)
-          else {
+          else if (pre.derivesFrom(defn.DynamicClass)) {
+            TryDynamicCallType
+          } else {
             val alts = tpe.denot.alternatives.map(_.symbol).filter(_.exists)
             val what = alts match {
               case Nil =>
diff --git a/src/dotty/tools/dotc/typer/Typer.scala b/src/dotty/tools/dotc/typer/Typer.scala
index fdcfe347b..2cfc5f411 100644
--- a/src/dotty/tools/dotc/typer/Typer.scala
+++ b/src/dotty/tools/dotc/typer/Typer.scala
@@ -317,12 +317,9 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
       val qual1 = typedExpr(tree.qualifier, selectionProto(tree.name, pt, this))
       if (tree.name.isTypeName) checkStable(qual1.tpe, qual1.pos)
       val select = typedSelect(tree, pt, qual1)
-      pt match {
-        case _: FunProto | AssignProto => select
-        case _ =>
-          if (select.tpe eq TryDynamicCallType) typedDynamicSelect(tree, pt)
-          else select
-      }
+      if (select.tpe ne TryDynamicCallType) select
+      else if (pt.isInstanceOf[PolyProto] || pt.isInstanceOf[FunProto] || pt == AssignProto) select
+      else typedDynamicSelect(tree, Nil, pt)
    }
 
     def asJavaSelectFromTypeTree(implicit ctx: Context): Tree = {
@@ -518,11 +515,7 @@ class Typer extends Namer with TypeAssigner with Applications with Implicits wit
                     reassignmentToVal
                 }
               case TryDynamicCallType =>
-                tree match {
-                  case Assign(Select(qual, name), rhs) if !isDynamicMethod(name) =>
-                    typedDynamicAssign(qual, name, rhs, pt)
-                  case _ => reassignmentToVal
-                }
+                typedDynamicAssign(tree, pt)
               case tpe =>
                 reassignmentToVal
             }