Typing by-name parameters with ExprTypes.

To avoid duplication between by-name parameters and expr types, we treat by-name parameters as as having ExprType. A part of this is introducing ByNameTypeTree, a specific tree class for => T types.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/dotty/tools/dotc/parsing/Parsers.scala b/src/dotty/tools/dotc/parsing/Parsers.scala
index 85289ee0f..f3f87daff 100644
--- a/src/dotty/tools/dotc/parsing/Parsers.scala
+++ b/src/dotty/tools/dotc/parsing/Parsers.scala
@@ -647,7 +647,7 @@ object Parsers {
               atPos(start, in.skipToken()) { Function(ts, typ()) }
             else {
               for (t <- ts)
-                if (isByNameParamType(t))
+                if (t.isInstanceOf[ByNameTypeTree])
                   syntaxError("no by-name parameter type allowed here", t.pos)
               val tuple = atPos(start) { makeTupleOrParens(ts) }
               infixTypeRest(refinedTypeRest(withTypeRest(simpleTypeRest(tuple))))
@@ -748,7 +748,7 @@ object Parsers {
     /** FunArgType ::=  ArgType | `=>' ArgType
      */
     val funArgType = () =>
-      if (in.token == ARROW) atPos(in.skipToken()) { PrefixOp(nme.ARROWkw, argType()) }
+      if (in.token == ARROW) atPos(in.skipToken()) { ByNameTypeTree(argType()) }
       else argType()
 
     /** ParamType ::= FunArgType | ArgType `*'