Merge pull request #9863 from dotty-staging/refactor-Reflect-implicit-search

Refactor Reflect implicit search

Author: nicolasstucki

community-build/community-projects/shapeless

@@ -11,7 +11,6 @@ import dotty.tools.dotc.core.NameKinds
 import dotty.tools.dotc.core.StdNames._
 import dotty.tools.dotc.quoted.reflect._
 import dotty.tools.dotc.core.Decorators._
-import dotty.tools.dotc.typer.Implicits
 
 import scala.quoted.QuoteContext
 import scala.quoted.show.SyntaxHighlight
@@ -2173,10 +2172,12 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext:
       end extension
     end ConstantMethodsImpl
 
-    type ImplicitSearchResult = Tree
+    object Implicits extends ImplicitsModule:
+      def search(tpe: Type): ImplicitSearchResult =
+        ctx.typer.inferImplicitArg(tpe, rootPosition.span)
+    end Implicits
 
-    def searchImplicit(tpe: Type): ImplicitSearchResult =
-      ctx.typer.inferImplicitArg(tpe, rootPosition.span)
+    type ImplicitSearchResult = Tree
 
     type ImplicitSearchSuccess = Tree
 
@@ -2185,7 +2186,7 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext:
       override def unapply(x: Any): Option[ImplicitSearchSuccess] = x match
         case x: Tree @unchecked =>
           x.tpe match
-            case _: Implicits.SearchFailureType => None
+            case _: dotc.typer.Implicits.SearchFailureType => None
             case _ => Some(x)
         case _ => None
     end ImplicitSearchSuccessTypeTest
@@ -2203,15 +2204,15 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext:
       override def unapply(x: Any): Option[ImplicitSearchFailure] = x match
         case x: Tree @unchecked =>
           x.tpe match
-            case _: Implicits.SearchFailureType => Some(x)
+            case _: dotc.typer.Implicits.SearchFailureType => Some(x)
             case _ => None
         case _ => None
     end ImplicitSearchFailureTypeTest
 
     object ImplicitSearchFailureMethodsImpl extends ImplicitSearchFailureMethods:
       extension (self: ImplicitSearchFailure):
         def explanation: String =
-          self.tpe.asInstanceOf[Implicits.SearchFailureType].explanation
+          self.tpe.asInstanceOf[dotc.typer.Implicits.SearchFailureType].explanation
       end extension
     end ImplicitSearchFailureMethodsImpl
 
@@ -2222,7 +2223,7 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext:
       override def unapply(x: Any): Option[DivergingImplicit] = x match
         case x: Tree @unchecked =>
           x.tpe match
-            case _: Implicits.DivergingImplicit => Some(x)
+            case _: dotc.typer.Implicits.DivergingImplicit => Some(x)
             case _ => None
         case _ => None
     end DivergingImplicitTypeTest
@@ -2234,7 +2235,7 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext:
       override def unapply(x: Any): Option[NoMatchingImplicits] = x match
         case x: Tree @unchecked =>
           x.tpe match
-            case _: Implicits.NoMatchingImplicits => Some(x)
+            case _: dotc.typer.Implicits.NoMatchingImplicits => Some(x)
             case _ => None
         case _ => None
     end NoMatchingImplicitsTypeTest
@@ -2246,7 +2247,7 @@ class QuoteContextImpl private (ctx: Context) extends QuoteContext:
       override def unapply(x: Any): Option[AmbiguousImplicits] = x match
         case x: Tree @unchecked =>
           x.tpe match
-            case _: Implicits.AmbiguousImplicits => Some(x)
+            case _: dotc.typer.Implicits.AmbiguousImplicits => Some(x)
             case _ => None
         case _ => None
     end AmbiguousImplicitsTypeTest

compiler/src/dotty/tools/dotc/quoted/QuoteContextImpl.scala

@@ -182,7 +182,7 @@ object Expr {
     ofTupleFromSeq(elems).asExprOf[Tuple.InverseMap[T, Expr]]
   }
 
-  /** Find an implicit of type `T` in the current scope given by `qctx`.
+  /** Find a given instance of type `T` in the current scope.
    *  Return `Some` containing the expression of the implicit or
    * `None` if implicit resolution failed.
    *
@@ -192,7 +192,7 @@ object Expr {
    */
   def summon[T](using tpe: Type[T])(using qctx: QuoteContext): Option[Expr[T]] = {
     import qctx.tasty._
-    searchImplicit(tpe.unseal.tpe) match {
+    Implicits.search(tpe.unseal.tpe) match {
       case iss: ImplicitSearchSuccess => Some(iss.tree.seal.asInstanceOf[Expr[T]])
       case isf: ImplicitSearchFailure => None
     }

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

@@ -2493,15 +2493,18 @@ trait Reflection { reflection =>
   // IMPLICIT SEARCH //
   /////////////////////
 
-  // TODO: this should not be top level
-  /** Find an implicit of type `T` in the current scope given by `ctx`.
-   *  Return an `ImplicitSearchResult`.
-   *
-   *  @param tpe type of the implicit parameter
-   *  @param ctx current context
-   */
-  def searchImplicit(tpe: Type): ImplicitSearchResult
+  val Implicits: ImplicitsModule
+
+  trait ImplicitsModule { self: Implicits.type =>
+    /** Find a given instance of type `T` in the current scope provided by the current enclosing splice.
+     *  Return an `ImplicitSearchResult`.
+     *
+     *  @param tpe type of the implicit parameter
+     */
+    def search(tpe: Type): ImplicitSearchResult
+  }
 
+  /** Result of a given instance search */
   type ImplicitSearchResult <: AnyRef
 
   given TypeTest[ImplicitSearchResult, ImplicitSearchSuccess] = ImplicitSearchSuccessTypeTest

library/src/scala/tasty/Reflection.scala

@@ -5,7 +5,7 @@ inline def f: Any = ${ fImpl }
 
 private def fImpl(using qctx: QuoteContext): Expr[Unit] = {
   import qctx.tasty._
-  searchImplicit(('[A]).unseal.tpe) match {
+  Implicits.search(('[A]).unseal.tpe) match {
     case x: ImplicitSearchSuccess =>
       '{}
     case x: DivergingImplicit => '{}

tests/neg-macros/delegate-match-1/Macro_1.scala

@@ -5,7 +5,7 @@ inline def f: Any = ${ fImpl }
 
 private def fImpl (using qctx: QuoteContext) : Expr[Unit] = {
   import qctx.tasty._
-  searchImplicit(('[A]).unseal.tpe) match {
+  Implicits.search(('[A]).unseal.tpe) match {
     case x: ImplicitSearchSuccess =>
       '{}
     case x: DivergingImplicit => '{}

tests/neg-macros/delegate-match-2/Macro_1.scala

@@ -5,7 +5,7 @@ inline def f: Any = ${ fImpl }
 
 private def fImpl(using qctx: QuoteContext) : Expr[Unit] = {
   import qctx.tasty._
-  searchImplicit(('[A]).unseal.tpe) match {
+  Implicits.search(('[A]).unseal.tpe) match {
     case x: ImplicitSearchSuccess =>
       '{}
     case x: DivergingImplicit => '{}