New type lambda scheme for hk types

1 files changed, 10 insertions, 1 deletions

diff --git a/src/dotty/tools/dotc/parsing/Parsers.scala b/src/dotty/tools/dotc/parsing/Parsers.scala
index ded17c67c..0cc392bad 100644
--- a/src/dotty/tools/dotc/parsing/Parsers.scala
+++ b/src/dotty/tools/dotc/parsing/Parsers.scala
@@ -223,7 +223,9 @@ object Parsers {
       } // DEBUG
 
     private def expectedMsg(token: Int): String =
-      showToken(token) + " expected but " + showToken(in.token) + " found."
+      expectedMessage(showToken(token))
+    private def expectedMessage(what: String): String =
+      s"$what expected but ${showToken(in.token)} found"
 
     /** Consume one token of the specified type, or
       * signal an error if it is not there.
@@ -648,6 +650,7 @@ object Parsers {
 /* ------------- TYPES ------------------------------------------------------ */
 
     /** Type        ::= FunArgTypes `=>' Type
+     *                |  HkTypeParamClause `->' Type
      *                | InfixType
      *  FunArgTypes ::=  InfixType
      *                | `(' [ FunArgType {`,' FunArgType } ] `)'
@@ -677,6 +680,12 @@ object Parsers {
             }
           }
         }
+        else if (in.token == LBRACKET) {
+          val tparams = typeParamClause(ParamOwner.TypeParam)
+          if (isIdent && in.name.toString == "->")
+            atPos(in.skipToken())(TypeLambdaTree(tparams, typ()))
+          else { syntaxErrorOrIncomplete(expectedMessage("`->'")); typ() }
+        }
         else infixType()
 
       in.token match {