Add apply methods to import selectors in Quotes #21225 (#22457)

For now added as experimental. Fixes #21225

Author: jchyb

Diff for: compiler/src/scala/quoted/runtime/impl/QuotesImpl.scala

@@ -1694,6 +1694,8 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
     end SimpleSelectorTypeTest
 
     object SimpleSelector extends SimpleSelectorModule:
+      def apply(name: String): SimpleSelector = 
+        withDefaultPos(untpd.ImportSelector(untpd.Ident(name.toTermName)))
       def unapply(x: SimpleSelector): Some[String] = Some(x.name.toString)
     end SimpleSelector
 
@@ -1713,6 +1715,8 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
     end RenameSelectorTypeTest
 
     object RenameSelector extends RenameSelectorModule:
+      def apply(fromName: String, toName: String): RenameSelector =
+        withDefaultPos(untpd.ImportSelector(untpd.Ident(fromName.toTermName), untpd.Ident(toName.toTermName)))
       def unapply(x: RenameSelector): (String, String) = (x.fromName, x.toName)
     end RenameSelector
 
@@ -1738,6 +1742,8 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
     end OmitSelectorTypeTest
 
     object OmitSelector extends OmitSelectorModule:
+      def apply(name: String): OmitSelector =
+        withDefaultPos(untpd.ImportSelector(untpd.Ident(name.toTermName), untpd.Ident(nme.WILDCARD)))
       def unapply(x: OmitSelector): Some[String] = Some(x.imported.name.toString)
     end OmitSelector
 
@@ -1758,6 +1764,11 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
     end GivenSelectorTypeTest
 
     object GivenSelector extends GivenSelectorModule:
+      def apply(bound: Option[TypeTree]): GivenSelector =
+        withDefaultPos(untpd.ImportSelector(
+          untpd.Ident(nme.EMPTY),
+          bound = bound.map(tpt => untpd.TypedSplice(tpt)).getOrElse(EmptyTree)
+        ))
       def unapply(x: GivenSelector): Some[Option[TypeTree]] =
         Some(GivenSelectorMethods.bound(x))
     end GivenSelector

Diff for: library/src/scala/quoted/Quotes.scala

@@ -2544,6 +2544,7 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
 
     /** Methods of the module object `val SimpleSelector` */
     trait SimpleSelectorModule { this: SimpleSelector.type =>
+      @experimental def apply(name: String): SimpleSelector
       def unapply(x: SimpleSelector): Some[String]
     }
 
@@ -2569,6 +2570,7 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
 
     /** Methods of the module object `val RenameSelector` */
     trait RenameSelectorModule { this: RenameSelector.type =>
+      @experimental def apply(fromName: String, toName: String): RenameSelector
       def unapply(x: RenameSelector): (String, String)
     }
 
@@ -2596,6 +2598,7 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
 
     /** Methods of the module object `val OmitSelector` */
     trait OmitSelectorModule { this: OmitSelector.type =>
+      @experimental def apply(name: String): OmitSelector
       def unapply(x: OmitSelector): Some[String]
     }
 
@@ -2620,6 +2623,7 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
 
     /** Methods of the module object `val GivenSelector` */
     trait GivenSelectorModule { this: GivenSelector.type =>
+      @experimental def apply(bound: Option[TypeTree]): GivenSelector
       def unapply(x: GivenSelector): Some[Option[TypeTree]]
     }
 

Diff for: tests/run-macros/i21225.check

@@ -0,0 +1,2 @@
+bar codec
+foo codec

Diff for: tests/run-macros/i21225/Macro_1.scala

@@ -0,0 +1,33 @@
+//> using options -experimental
+
+import scala.quoted.*
+
+trait Codec[-T] { def print(): Unit }
+object Codec {
+  inline def derivedWithDeps[T](deps: Any): Codec[T] = ${derivedWithDepsImpl[T]('deps)}
+
+  private def derivedWithDepsImpl[T](deps: Expr[Any])(using q: Quotes)(using Type[T]): Expr[Codec[T]] = {
+    import q.reflect.*
+
+    val givenSelector: Selector = GivenSelector(None)
+    val theImport = Import(deps.asTerm, List(givenSelector))
+    Block(List(theImport), '{scala.compiletime.summonInline[Codec[T]]}.asTerm).asExprOf[Codec[T]]
+    /* import deps.given
+     * summonInline[Codec[T]]
+     */
+  }
+
+  inline def derivedWithDepsWithNamedOmitted[T](deps: Any): Codec[T] = ${derivedWithDepsWithNamedOmittedImpl[T]('deps)}
+
+  private def derivedWithDepsWithNamedOmittedImpl[T](deps: Expr[Any])(using q: Quotes)(using Type[T]): Expr[Codec[T]] = {
+    import q.reflect.*
+
+    val givenSelector: Selector = GivenSelector(None)
+    val omitSelector: Selector = OmitSelector("named")
+    val theImport = Import(deps.asTerm, List(givenSelector, omitSelector))
+    Block(List(theImport), '{scala.compiletime.summonInline[Codec[T]]}.asTerm).asExprOf[Codec[T]]
+    /* import deps.{given, named => _}
+     * summonInline[Codec[T]]
+     */
+  }
+}

Diff for: tests/run-macros/i21225/Test_2.scala

@@ -0,0 +1,14 @@
+//> using options -experimental
+
+import scala.quoted.*
+
+sealed trait Foo
+class Bar extends Foo
+object CustomCodecs {
+  given named: Codec[Bar] = new Codec[Bar] { def print(): Unit = println("bar codec")}
+  given Codec[Foo] = new Codec[Foo] { def print(): Unit = println("foo codec") }
+}
+
+@main def Test =
+  Codec.derivedWithDeps[Bar](CustomCodecs).print()
+  Codec.derivedWithDepsWithNamedOmitted[Bar](CustomCodecs).print()

Diff for: tests/run-tasty-inspector/stdlibExperimentalDefinitions.scala

@@ -73,6 +73,10 @@ val experimentalDefinitionInLibrary = Set(
   "scala.quoted.Quotes.reflectModule.MethodTypeMethods.hasErasedParams",
   "scala.quoted.Quotes.reflectModule.TermParamClauseMethods.erasedArgs",
   "scala.quoted.Quotes.reflectModule.TermParamClauseMethods.hasErasedArgs",
+  "scala.quoted.Quotes.reflectModule.GivenSelectorModule.apply",
+  "scala.quoted.Quotes.reflectModule.OmitSelectorModule.apply",
+  "scala.quoted.Quotes.reflectModule.RenameSelectorModule.apply",
+  "scala.quoted.Quotes.reflectModule.SimpleSelectorModule.apply",
 
   // New feature: fromNullable for explicit nulls
   "scala.Predef$.fromNullable",