Merge pull request #11143 from dotty-staging/fix-#11124

Fix reflect ByName docs and align method names

Author: nicolasstucki

compiler/src-bootstrapped/scala/quoted/runtime/impl/QuotesImpl.scala

@@ -1611,7 +1611,8 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
         def =:=(that: TypeRepr): Boolean = self =:= that
         def <:<(that: TypeRepr): Boolean = self <:< that
         def widen: TypeRepr = self.widen
-        def widenTermRefExpr: TypeRepr = self.widenTermRefExpr
+        def widenTermRefByName: TypeRepr = self.widenTermRefExpr
+        def widenByName: TypeRepr = self.widenExpr
         def dealias: TypeRepr = self.dealias
         def simplified: TypeRepr = self.simplified
         def classSymbol: Option[Symbol] =

compiler/src/scala/quoted/runtime/impl/Matcher.scala

@@ -209,7 +209,7 @@ object Matcher {
               case Block(List(DefDef("$anonfun", _, _, _, Some(Apply(Ident(name), _)))), _) => name
               case arg => arg.symbol.name
             }
-            val argTypes = args.map(x => x.tpe.widenTermRefExpr)
+            val argTypes = args.map(x => x.tpe.widenTermRefByName)
             val resType = pattern.tpe
             val res = Lambda(Symbol.spliceOwner, MethodType(names)(_ => argTypes, _ => resType), (meth, x) => bodyFn(x).changeOwner(meth))
             matched(res.asExpr)

library/src-bootstrapped/scala/quoted/Quotes.scala

@@ -2089,25 +2089,25 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
         def <:<(that: TypeRepr): Boolean
 
         /** Widen from singleton type to its underlying non-singleton
-        *  base type by applying one or more `underlying` dereferences,
-        *  Also go from => T to T.
-        *  Identity for all other types. Example:
-        *
-        *  class Outer { class C ; val x: C }
-        *  def o: Outer
-        *  <o.x.type>.widen = o.C
-        */
+         *  base type by applying one or more `underlying` dereferences,
+         *  Also go from => T to T.
+         *  Identity for all other types. Example:
+         *
+         *  class Outer { class C ; val x: C }
+         *  def o: Outer
+         *  <o.x.type>.widen = o.C
+         */
         def widen: TypeRepr
 
         /** Widen from TermRef to its underlying non-termref
-          *  base type, while also skipping `=>T` types.
-          */
-        def widenTermRefExpr: TypeRepr
+         *  base type, while also skipping ByName types.
+         */
+        def widenTermRefByName: TypeRepr
 
-        /** Follow aliases and dereferences LazyRefs, annotated types and instantiated
-          *  TypeVars until type is no longer alias type, annotated type, LazyRef,
-          *  or instantiated type variable.
-          */
+        /** Widen from ByName type to its result type. */
+        def widenByName: TypeRepr
+
+        /** Follow aliases, annotated types until type is no longer alias type, annotated type. */
         def dealias: TypeRepr
 
         /** A simplified version of this type which is equivalent wrt =:= to this type.
@@ -2439,7 +2439,18 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
       end extension
     end MatchTypeMethods
 
-    /** Type of a by by name parameter */
+    /** Type of a by-name definition of type `=>T`.
+     *
+     *  May represent by-name parameter such as `thunk` in
+     *  ```scala
+     *    def log[T](thunk: =>T): T = ...
+     *  ```
+     *
+     *  May also represent a the return type of a parameterless method definition such as
+     *  ```scala
+     *    def foo: Int = ...
+     *  ```
+     */
     type ByNameType <: TypeRepr
 
     /** `TypeTest` that allows testing at runtime in a pattern match if a `TypeRepr` is a `ByNameType` */

library/src-non-bootstrapped/scala/quoted/Quotes.scala

@@ -1368,6 +1368,7 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
         def widen: TypeRepr
 
         def widenTermRefExpr: TypeRepr
+        def widenTermRefByName: TypeRepr = widenTermRefExpr
 
         def dealias: TypeRepr
 

tests/run-macros/refined-selectable-macro/Macro_1.scala

@@ -17,7 +17,7 @@ object Macro {
   private def toTupleImpl(s: Expr[Selectable])(using qctx:Quotes) : Expr[Tuple] = {
     import quotes.reflect._
 
-    val repr = s.asTerm.tpe.widenTermRefExpr.dealias
+    val repr = s.asTerm.tpe.widenTermRefByName.dealias
 
     def rec(tpe: TypeRepr): List[(String, TypeRepr)] = {
       tpe match {
@@ -51,7 +51,7 @@ object Macro {
   private def fromTupleImpl[T: Type](s: Expr[Tuple], newRecord: Expr[Array[(String, Any)] => T])(using qctx:Quotes) : Expr[Any] = {
     import quotes.reflect._
 
-    val repr = s.asTerm.tpe.widenTermRefExpr.dealias
+    val repr = s.asTerm.tpe.widenTermRefByName.dealias
 
     def isTupleCons(sym: Symbol): Boolean = sym.owner == defn.ScalaPackageClass && sym.name == "*:"