From 927e1508af213f89eac1d8297ec766defb263763 Mon Sep 17 00:00:00 2001
From: Martin Odersky <odersky@gmail.com>
Date: Mon, 26 Aug 2019 18:22:31 +0200
Subject: [PATCH] Fix #7103: Accept backquoted `as` as the name of a given

---
 compiler/src/dotty/tools/dotc/ast/Desugar.scala     | 2 +-
 compiler/src/dotty/tools/dotc/parsing/Parsers.scala | 2 +-
 tests/pos/i7103.scala                               | 3 +++
 3 files changed, 5 insertions(+), 2 deletions(-)
 create mode 100644 tests/pos/i7103.scala

diff --git a/compiler/src/dotty/tools/dotc/ast/Desugar.scala b/compiler/src/dotty/tools/dotc/ast/Desugar.scala
index bd3938b1aeaa..f678d8e0cfe9 100644
--- a/compiler/src/dotty/tools/dotc/ast/Desugar.scala
+++ b/compiler/src/dotty/tools/dotc/ast/Desugar.scala
@@ -957,7 +957,7 @@ object desugar {
           case Some(DefDef(name, _, (vparam :: _) :: _, _, _)) =>
             s"${name}_of_${inventTypeName(vparam.tpt)}"
           case _ =>
-            ctx.error(i"anonymous instance must have `for` part or must define at least one extension method", impl.sourcePos)
+            ctx.error(i"anonymous instance must have `as` part or must define at least one extension method", impl.sourcePos)
             nme.ERROR.toString
         }
       else
diff --git a/compiler/src/dotty/tools/dotc/parsing/Parsers.scala b/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
index 4b1bc583c746..b6cf173a1227 100644
--- a/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
+++ b/compiler/src/dotty/tools/dotc/parsing/Parsers.scala
@@ -2873,7 +2873,7 @@ object Parsers {
      */
     def instanceDef(newStyle: Boolean, start: Offset, mods: Modifiers, instanceMod: Mod) = atSpan(start, nameStart) {
       var mods1 = addMod(mods, instanceMod)
-      val name = if (isIdent && (!newStyle || in.name != nme.as)) ident() else EmptyTermName
+      val name = if (isIdent && !(newStyle && isIdent(nme.as))) ident() else EmptyTermName
       val tparams = typeParamClauseOpt(ParamOwner.Def)
       var leadingParamss =
         if (in.token == LPAREN)
diff --git a/tests/pos/i7103.scala b/tests/pos/i7103.scala
new file mode 100644
index 000000000000..edc0f5220ead
--- /dev/null
+++ b/tests/pos/i7103.scala
@@ -0,0 +1,3 @@
+class X
+object X extends X
+given `as` as X = X
\ No newline at end of file