Overcoming limitations of the repl, multiple-tr...

Overcoming limitations of the repl, multiple-tree lines and assignments.

The best part of nicely documented limitations is that you can stare at
the same comment for years and then the day comes when you give it the
heave-ho.

Exhibit A (regarding a single bare expression): "This is necessary due
to it being hard to modify code at a textual level, and it being hard
to submit an AST to the compiler." Yes, it IS hard to modify code at
a textual level (see enclosed patch) but we won't let that stop us
anymore. Closes #4578.

Exhibit B (regarding the left hand side of assignments having to be
Ident): "An unfortunate limitation." Unfortunate no longer! No review.

1 files changed, 10 insertions, 10 deletions

diff --git a/src/compiler/scala/tools/nsc/interpreter/MemberHandlers.scala b/src/compiler/scala/tools/nsc/interpreter/MemberHandlers.scala
index 99112d9151..33f21165b4 100644
--- a/src/compiler/scala/tools/nsc/interpreter/MemberHandlers.scala
+++ b/src/compiler/scala/tools/nsc/interpreter/MemberHandlers.scala
@@ -52,15 +52,15 @@ trait MemberHandlers {
   }
 
   def chooseHandler(member: Tree): MemberHandler = member match {
-    case member: DefDef               => new DefHandler(member)
-    case member: ValDef               => new ValHandler(member)
-    case member@Assign(Ident(_), _)   => new AssignHandler(member)
-    case member: ModuleDef            => new ModuleHandler(member)
-    case member: ClassDef             => new ClassHandler(member)
-    case member: TypeDef              => new TypeAliasHandler(member)
-    case member: Import               => new ImportHandler(member)
-    case DocDef(_, documented)        => chooseHandler(documented)
-    case member                       => new GenericHandler(member)
+    case member: DefDef        => new DefHandler(member)
+    case member: ValDef        => new ValHandler(member)
+    case member: Assign        => new AssignHandler(member)
+    case member: ModuleDef     => new ModuleHandler(member)
+    case member: ClassDef      => new ClassHandler(member)
+    case member: TypeDef       => new TypeAliasHandler(member)
+    case member: Import        => new ImportHandler(member)
+    case DocDef(_, documented) => chooseHandler(documented)
+    case member                => new GenericHandler(member)
   }
 
   sealed abstract class MemberDefHandler(override val member: MemberDef) extends MemberHandler(member) {
@@ -129,7 +129,7 @@ trait MemberHandlers {
   }
 
   class AssignHandler(member: Assign) extends MemberHandler(member) {
-    val lhs = member.lhs.asInstanceOf[Ident] // an unfortunate limitation
+    val Assign(lhs, rhs) = member
     val name = newTermName(freshInternalVarName())
 
     override def definesTerm = Some(name)