Add second field to SeqLiteral

The field keeps track of the element type. This is necessary
because JavaSeqLiteral is nonvariant and the elements might
be empty, so we cannot always compute the type from the
element types.

1 files changed, 11 insertions, 11 deletions

diff --git a/src/dotty/tools/dotc/ast/tpd.scala b/src/dotty/tools/dotc/ast/tpd.scala
index 9a6f74331..a6d97478b 100644
--- a/src/dotty/tools/dotc/ast/tpd.scala
+++ b/src/dotty/tools/dotc/ast/tpd.scala
@@ -123,14 +123,11 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
   def Try(block: Tree, cases: List[CaseDef], finalizer: Tree)(implicit ctx: Context): Try =
     ta.assignType(untpd.Try(block, cases, finalizer), block, cases)
 
-  def SeqLiteral(elems: List[Tree])(implicit ctx: Context): SeqLiteral =
-    ta.assignType(untpd.SeqLiteral(elems), elems)
+  def SeqLiteral(elems: List[Tree], elemtpt: Tree)(implicit ctx: Context): SeqLiteral =
+    ta.assignType(untpd.SeqLiteral(elems, elemtpt), elems, elemtpt)
 
-  def SeqLiteral(tpe: Type, elems: List[Tree])(implicit ctx: Context): SeqLiteral =
-    if (tpe derivesFrom defn.SeqClass) SeqLiteral(elems) else JavaSeqLiteral(elems)
-
-  def JavaSeqLiteral(elems: List[Tree])(implicit ctx: Context): SeqLiteral =
-    ta.assignType(new untpd.JavaSeqLiteral(elems), elems)
+  def JavaSeqLiteral(elems: List[Tree], elemtpt: Tree)(implicit ctx: Context): SeqLiteral =
+    ta.assignType(new untpd.JavaSeqLiteral(elems, elemtpt), elems, elemtpt)
 
   def TypeTree(original: Tree)(implicit ctx: Context): TypeTree =
     TypeTree(original.tpe, original)
@@ -564,11 +561,14 @@ object tpd extends Trees.Instance[Type] with TypedTreeInfo {
       }
     }
 
-    override def SeqLiteral(tree: Tree)(elems: List[Tree])(implicit ctx: Context): SeqLiteral = {
-      val tree1 = untpd.cpy.SeqLiteral(tree)(elems)
+    override def SeqLiteral(tree: Tree)(elems: List[Tree], elemtpt: Tree)(implicit ctx: Context): SeqLiteral = {
+      val tree1 = untpd.cpy.SeqLiteral(tree)(elems, elemtpt)
       tree match {
-        case tree: SeqLiteral if sameTypes(elems, tree.elems) => tree1.withTypeUnchecked(tree.tpe)
-        case _ => ta.assignType(tree1, elems)
+        case tree: SeqLiteral
+        if sameTypes(elems, tree.elems) && (elemtpt.tpe eq tree.elemtpt.tpe) =>
+          tree1.withTypeUnchecked(tree.tpe)
+        case _ =>
+          ta.assignType(tree1, elems, elemtpt)
       }
     }