Fix #10359: Add GivenSelector to reflection API

Author: nicolasstucki

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

@@ -1474,7 +1474,7 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
 
     object SimpleSelectorTypeTest extends TypeTest[ImportSelector, SimpleSelector]:
       def unapply(x: ImportSelector): Option[SimpleSelector & x.type] = x match
-        case x: (untpd.ImportSelector & x.type) if x.renamed.isEmpty => Some(x)
+        case x: (untpd.ImportSelector & x.type) if x.renamed.isEmpty && !x.isGiven => Some(x)
         case _ => None // TODO: handle import bounds
     end SimpleSelectorTypeTest
 
@@ -1534,6 +1534,29 @@ class QuotesImpl private (using val ctx: Context) extends Quotes, QuoteUnpickler
       end extension
     end OmitSelectorMethodsImpl
 
+    type GivenSelector = untpd.ImportSelector
+
+    object GivenSelectorTypeTest extends TypeTest[ImportSelector, GivenSelector]:
+      def unapply(x: ImportSelector): Option[GivenSelector & x.type] = x match {
+        case self: (untpd.ImportSelector & x.type) if x.isGiven => Some(self)
+        case _ => None
+      }
+    end GivenSelectorTypeTest
+
+    object GivenSelector extends GivenSelectorModule:
+      def unapply(x: GivenSelector): Option[Option[TypeTree]] =
+        Some(GivenSelectorMethodsImpl.bound(x))
+    end GivenSelector
+
+    object GivenSelectorMethodsImpl extends GivenSelectorMethods:
+      extension (self: GivenSelector):
+        def bound: Option[TypeTree] =
+          self.bound match
+            case untpd.TypedSplice(tpt) => Some(tpt)
+            case _ => None
+      end extension
+    end GivenSelectorMethodsImpl
+
     type TypeRepr = dotc.core.Types.Type
 
     object TypeRepr extends TypeReprModule:

compiler/src/scala/quoted/runtime/impl/printers/Extractors.scala

@@ -237,6 +237,7 @@ object Extractors {
       case SimpleSelector(id) => this += "SimpleSelector(" += id += ")"
       case RenameSelector(id1, id2) => this += "RenameSelector(" += id1 += ", " += id2 += ")"
       case OmitSelector(id) => this += "OmitSelector(" += id += ")"
+      case GivenSelector(bound) => this += "GivenSelector(" += bound += ")"
     }
 
     def visitSymbol(x: Symbol): this.type =

compiler/src/scala/quoted/runtime/impl/printers/SourceCode.scala

@@ -1226,6 +1226,13 @@ object SourceCode {
       case SimpleSelector(name) => this += name
       case OmitSelector(name) => this += name += " => _"
       case RenameSelector(name, newName) => this += name += " => " += newName
+      case GivenSelector(bound) =>
+        bound match
+          case Some(tpt) =>
+            this += "given "
+            printTree(tpt)
+          case _ =>
+            this += "given"
     }
 
     private def printDefinitionName(tree: Definition): this.type = tree match {

library/src/scala/quoted/Quotes.scala

@@ -153,6 +153,7 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
    *  +- ImportSelector -+- SimpleSelector
    *                     +- RenameSelector
    *                     +- OmitSelector
+   *                     +- GivenSelector
    *
    *  +- Signature
    *
@@ -1735,13 +1736,17 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
     *   * SimpleSelector: `.bar` in `import foo.bar`
     *   * RenameSelector: `.{bar => baz}` in `import foo.{bar => baz}`
     *   * OmitSelector: `.{bar => _}` in `import foo.{bar => _}`
+    *   * GivneSelector: `.given`/`.{given T}` in `import foo.given`/`import foo.{given T}`
     */
     type ImportSelector <: AnyRef
 
     val ImportSelector: ImportSelectorModule
 
     trait ImportSelectorModule { this: ImportSelector.type => }
 
+    /** Simple import selector: `.bar` in `import foo.bar` */
+    type SimpleSelector <: ImportSelector
+
     given TypeTest[ImportSelector, SimpleSelector] = SimpleSelectorTypeTest
     protected val SimpleSelectorTypeTest: TypeTest[ImportSelector, SimpleSelector]
 
@@ -1751,9 +1756,6 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
       def unapply(x: SimpleSelector): Option[String]
     }
 
-    /** Simple import selector: `.bar` in `import foo.bar` */
-    type SimpleSelector <: ImportSelector
-
     given SimpleSelectorMethods as SimpleSelectorMethods = SimpleSelectorMethodsImpl
     protected val SimpleSelectorMethodsImpl: SimpleSelectorMethods
 
@@ -1776,9 +1778,6 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
       def unapply(x: RenameSelector): Option[(String, String)]
     }
 
-    /** Omit import selector: `.{bar => _}` in `import foo.{bar => _}` */
-    type OmitSelector <: ImportSelector
-
     given RenameSelectorMethods as RenameSelectorMethods = RenameSelectorMethodsImpl
     protected val RenameSelectorMethodsImpl: RenameSelectorMethods
 
@@ -1791,6 +1790,9 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
       end extension
     end RenameSelectorMethods
 
+    /** Omit import selector: `.{bar => _}` in `import foo.{bar => _}` */
+    type OmitSelector <: ImportSelector
+
     given TypeTest[ImportSelector, OmitSelector] = OmitSelectorTypeTest
     protected val OmitSelectorTypeTest: TypeTest[ImportSelector, OmitSelector]
 
@@ -1809,6 +1811,26 @@ trait Quotes { self: runtime.QuoteUnpickler & runtime.QuoteMatching =>
         def namePos: Position
     end OmitSelectorMethods
 
+    /** Omit import selector: `.given`/`.{given T}` in `import foo.given`/`import foo.{given T}` */
+    type GivenSelector <: ImportSelector
+
+    given TypeTest[ImportSelector, GivenSelector] = GivenSelectorTypeTest
+    protected val GivenSelectorTypeTest: TypeTest[ImportSelector, GivenSelector]
+
+    val GivenSelector: GivenSelectorModule
+
+    trait GivenSelectorModule { this: GivenSelector.type =>
+      def unapply(x: GivenSelector): Option[Option[TypeTree]]
+    }
+
+    given GivenSelectorMethods as GivenSelectorMethods = GivenSelectorMethodsImpl
+    protected val GivenSelectorMethodsImpl: GivenSelectorMethods
+
+    trait GivenSelectorMethods:
+      extension (self: GivenSelector):
+        def bound: Option[TypeTree]
+    end GivenSelectorMethods
+
     ///////////////
     //   TYPES   //
     ///////////////

tests/run-custom-args/tasty-inspector/i10359.scala

@@ -0,0 +1,46 @@
+import scala.quoted._
+import scala.tasty.inspector._
+
+object Bar {
+  class Givens {
+    given Int = 23
+    given String = "the string"
+  }
+  class Foo {
+    val g: Givens = Givens()
+    import g.given
+    import g.{given}
+    import g.{given Int}
+  }
+}
+
+// Case object implementation
+sealed trait Flavor
+case object Vanilla extends Flavor
+case object Chocolate extends Flavor
+case object Bourbon extends Flavor
+
+object Test {
+  def main(args: Array[String]): Unit = {
+    // Artefact of the current test infrastructure
+    // TODO improve infrastructure to avoid needing this code on each test
+    val classpath = dotty.tools.dotc.util.ClasspathFromClassloader(this.getClass.getClassLoader).split(java.io.File.pathSeparator).find(_.contains("runWithCompiler")).get
+    val allTastyFiles = dotty.tools.io.Path(classpath).walkFilter(_.extension == "tasty").map(_.toString).toList
+    val tastyFiles = allTastyFiles.filter(_.contains("TraitParams"))
+
+    val inspect = new TestInspector()
+    inspect.inspectTastyFiles(allTastyFiles.filter(_.contains("Bar")))
+  }
+}
+
+class TestInspector() extends TastyInspector:
+
+  protected def processCompilationUnit(using Quotes)(root: qctx.reflect.Tree): Unit =
+    import qctx.reflect._
+
+    val code = root.show
+    assert(code.contains("import Foo.this.g.{given}"), code)
+    assert(code.contains("import Foo.this.g.{given scala.Int}"), code)
+
+    val extractors = root.showExtractors
+    assert(extractors.contains("GivenSelector"), extractors)