Drop outdated syntax for given import selectors

It is `given _`, or `given Type`, never `given` alone.

Author: odersky

compiler/src/dotty/tools/dotc/ast/TreeInfo.scala

@@ -868,7 +868,7 @@ trait TypedTreeInfo extends TreeInfo[Type] { self: Trees.Instance[Type] =>
   /** Extractor for not-null assertions.
    *  A not-null assertion for reference `x` has the form `x.$asInstanceOf$[x.type & T]`.
    */
-  object AssertNotNull with
+  object AssertNotNull :
     def apply(tree: tpd.Tree, tpnn: Type)(using Context): tpd.Tree =
       tree.select(defn.Any_typeCast).appliedToType(AndType(tree.tpe, tpnn))
 

compiler/src/dotty/tools/dotc/core/Contexts.scala

@@ -16,7 +16,7 @@ import ast.untpd
 import Flags.GivenOrImplicit
 import util.{NoSource, SimpleIdentityMap, SourceFile}
 import typer.{Implicits, ImportInfo, Inliner, NamerContextOps, SearchHistory, SearchRoot, TypeAssigner, Typer, Nullables}
-import Nullables.{NotNullInfo, given}
+import Nullables.{NotNullInfo, given _}
 import Implicits.ContextualImplicits
 import config.Settings._
 import config.Config
@@ -599,7 +599,7 @@ object Contexts {
     def setDebug: this.type = setSetting(base.settings.Ydebug, true)
   }
 
-  extension ops on (c: Context) with
+  extension ops on (c: Context):
     def addNotNullInfo(info: NotNullInfo) =
       c.withNotNullInfos(c.notNullInfos.extendWith(info))
 

compiler/src/dotty/tools/dotc/parsing/Parsers.scala

@@ -3022,43 +3022,37 @@ object Parsers {
      */
     def importExpr(mkTree: ImportConstr): () => Tree = {
 
-      /** '_' | 'given'
-       */
-      def wildcardSelectorId() =
-        val name = if in.token == GIVEN then nme.EMPTY else nme.WILDCARD
-        atSpan(in.skipToken()) { Ident(name) }
+      /** '_' */
+      def wildcardSelectorId(name: TermName) = atSpan(in.skipToken()) { Ident(name) }
 
       /** ImportSelectors  ::=  id [‘=>’ id | ‘=>’ ‘_’] [‘,’ ImportSelectors]
        *                     |  WildCardSelector {‘,’ WildCardSelector}
        *  WildCardSelector ::=  ‘given’ (‘_' | InfixType)
        *                     |  ‘_'
        */
       def importSelectors(idOK: Boolean): List[ImportSelector] =
-        val selToken = in.token
-        val isWildcard = selToken == USCORE || selToken == GIVEN
-        val selector =
-          if isWildcard then
-            val id = wildcardSelectorId()
-            if selToken == USCORE then ImportSelector(id)
-            else atSpan(startOffset(id)) {
+        val isWildcard = in.token == USCORE || in.token == GIVEN
+        val selector = atSpan(in.offset) {
+          in.token match
+            case USCORE =>
+              ImportSelector(wildcardSelectorId(nme.WILDCARD))
+            case GIVEN =>
+              val id = wildcardSelectorId(nme.EMPTY)
               if in.token == USCORE then
                 in.nextToken()
                 ImportSelector(id)
-              else if in.token != RBRACE && in.token != COMMA then
-                ImportSelector(id, bound = infixType())
               else
-                ImportSelector(id)  // TODO: drop
-            }
-          else
-            val from = termIdent()
-            if !idOK then syntaxError(i"named imports cannot follow wildcard imports")
-            if in.token == ARROW then
-              atSpan(startOffset(from), in.skipToken()) {
-                val to = if in.token == USCORE then wildcardIdent() else termIdent()
-                ImportSelector(from, if to.name == nme.ERROR then EmptyTree else to)
-              }
-            else ImportSelector(from)
-
+                ImportSelector(id, bound = infixType())
+            case _ =>
+              val from = termIdent()
+              if !idOK then syntaxError(i"named imports cannot follow wildcard imports")
+              if in.token == ARROW then
+                atSpan(startOffset(from), in.skipToken()) {
+                  val to = if in.token == USCORE then wildcardIdent() else termIdent()
+                  ImportSelector(from, if to.name == nme.ERROR then EmptyTree else to)
+                }
+              else ImportSelector(from)
+        }
         val rest =
           if in.token == COMMA then
             in.nextToken()
@@ -3069,8 +3063,8 @@ object Parsers {
 
       val handleImport: Tree => Tree = tree =>
         in.token match
-          case USCORE | GIVEN =>
-            mkTree(tree, ImportSelector(wildcardSelectorId()) :: Nil)
+          case USCORE =>
+            mkTree(tree, ImportSelector(wildcardSelectorId(nme.WILDCARD)) :: Nil)
           case LBRACE =>
             mkTree(tree, inBraces(importSelectors(idOK = true)))
           case _ =>

compiler/src/dotty/tools/dotc/semanticdb/ExtractSemanticDB.scala

@@ -27,7 +27,7 @@ import scala.annotation.{ threadUnsafe => tu, tailrec }
  *  for a description of the format.
  *  TODO: Also extract type information
  */
-class ExtractSemanticDB extends Phase with
+class ExtractSemanticDB extends Phase:
   import Scala3.{_, given _}
   import Symbols.{given _}
 
@@ -46,7 +46,7 @@ class ExtractSemanticDB extends Phase with
     ExtractSemanticDB.write(unit.source, extract.occurrences.toList, extract.symbolInfos.toList)
 
   /** Extractor of symbol occurrences from trees */
-  class Extractor extends TreeTraverser with
+  class Extractor extends TreeTraverser:
 
     private var nextLocalIdx: Int = 0
 
@@ -57,7 +57,7 @@ class ExtractSemanticDB extends Phase with
     private val localBodies = mutable.HashMap[Symbol, Tree]()
 
     /** The local symbol(s) starting at given offset */
-    private val symsAtOffset = new mutable.HashMap[Int, Set[Symbol]]() with
+    private val symsAtOffset = new mutable.HashMap[Int, Set[Symbol]]():
       override def default(key: Int) = Set[Symbol]()
 
     /** The extracted symbol occurrences */
@@ -242,7 +242,7 @@ class ExtractSemanticDB extends Phase with
         name => locals.keys.find(local => local.isTerm && local.owner == funSym && local.name == name)
                       .fold("<?>")(Symbols.LocalPrefix + _)
 
-    private object PatternValDef with
+    private object PatternValDef:
 
       def unapply(tree: ValDef)(using Context): Option[(Tree, Tree)] = tree.rhs match
 
@@ -570,7 +570,7 @@ class ExtractSemanticDB extends Phase with
           registerSymbol(vparam.symbol, symbolName(vparam.symbol), symkinds)
         traverseTpt(vparam.tpt)
 
-object ExtractSemanticDB with
+object ExtractSemanticDB:
   import java.nio.file.Path
   import scala.collection.JavaConverters._
   import java.nio.file.Files

compiler/src/dotty/tools/dotc/semanticdb/Scala3.scala

@@ -15,17 +15,17 @@ import java.lang.Character.{isJavaIdentifierPart, isJavaIdentifierStart}
 import scala.annotation.internal.sharable
 import scala.annotation.switch
 
-object Scala3 with
+object Scala3:
   import Symbols._
-  import core.NameOps.given
+  import core.NameOps.{given _}
 
   @sharable private val unicodeEscape = raw"\$$u(\p{XDigit}{4})".r
   @sharable private val locals        = raw"local(\d+)".r
   @sharable private val ctor          = raw"[^;].*`<init>`\((?:\+\d+)?\)\.".r
 
   private val WILDCARDTypeName = nme.WILDCARD.toTypeName
 
-  enum SymbolKind derives Eql with
+  enum SymbolKind derives Eql:
     kind =>
 
     case Val, Var, Setter, Abstract
@@ -38,13 +38,13 @@ object Scala3 with
 
   end SymbolKind
 
-  object SymbolKind with
+  object SymbolKind:
     val ValSet   = Set(Val)
     val VarSet   = Set(Var)
     val emptySet = Set.empty[SymbolKind]
   end SymbolKind
 
-  object Symbols with
+  object Symbols:
 
     val RootPackage: String = "_root_/"
     val EmptyPackage: String = "_empty_/"
@@ -67,7 +67,7 @@ object Scala3 with
 
   end Symbols
 
-  extension NameOps on (name: Name) with
+  extension NameOps on (name: Name):
 
     def isWildcard = name match
       case nme.WILDCARD | WILDCARDTypeName => true
@@ -89,7 +89,7 @@ object Scala3 with
 
   // end NameOps
 
-  extension SymbolOps on (sym: Symbol) with
+  extension SymbolOps on (sym: Symbol):
 
     def ifExists(using Context): Option[Symbol] = if sym.exists then Some(sym) else None
 
@@ -128,7 +128,7 @@ object Scala3 with
 
   // end SymbolOps
 
-  object LocalSymbol with
+  object LocalSymbol:
 
     def unapply(symbolInfo: SymbolInformation): Option[Int] = symbolInfo.symbol match
       case locals(ints) =>
@@ -146,7 +146,7 @@ object Scala3 with
     case '/' | '.' | '#' | ']' | ')' => true
     case _                           => false
 
-  extension StringOps on (symbol: String) with
+  extension StringOps on (symbol: String):
 
     def isSymbol: Boolean = !symbol.isEmpty
     def isRootPackage: Boolean = RootPackage == symbol
@@ -171,7 +171,7 @@ object Scala3 with
 
   // end StringOps
 
-  extension InfoOps on (info: SymbolInformation) with
+  extension InfoOps on (info: SymbolInformation):
 
     def isAbstract: Boolean = (info.properties & SymbolInformation.Property.ABSTRACT.value) != 0
     def isFinal: Boolean = (info.properties & SymbolInformation.Property.FINAL.value) != 0
@@ -207,7 +207,7 @@ object Scala3 with
 
   // end InfoOps
 
-  extension RangeOps on (range: Range) with
+  extension RangeOps on (range: Range):
     def hasLength = range.endLine > range.startLine || range.endCharacter > range.startCharacter
   // end RangeOps
 
@@ -236,7 +236,7 @@ object Scala3 with
     *
     * taken from https://github.com/scalameta/scalameta/blob/master/semanticdb/metap/src/main/scala/scala/meta/internal/metap/IdentifierOrdering.scala
     */
-  private class IdentifierOrdering[T <: CharSequence] extends Ordering[T] with
+  private class IdentifierOrdering[T <: CharSequence] extends Ordering[T]:
 
     override def compare(o1: T, o2: T): Int =
       val len = math.min(o1.length(), o2.length())

compiler/src/dotty/tools/dotc/semanticdb/Tools.scala

@@ -4,9 +4,9 @@ import java.nio.file._
 import java.nio.charset.StandardCharsets
 import scala.collection.JavaConverters._
 import dotty.tools.dotc.util.SourceFile
-import dotty.tools.dotc.semanticdb.Scala3.{_, given}
+import dotty.tools.dotc.semanticdb.Scala3.{_, given _}
 
-object Tools with
+object Tools:
 
   /** Load SemanticDB TextDocument for a single Scala source file
    *

compiler/src/dotty/tools/dotc/transform/LiftTry.scala

@@ -78,5 +78,5 @@ class LiftTry extends MiniPhase with IdentityDenotTransformer { thisPhase =>
     }
     else tree
 }
-object LiftTry with
+object LiftTry:
   val name = "liftTry"

compiler/src/dotty/tools/dotc/typer/Applications.scala

@@ -22,7 +22,7 @@ import NameKinds.DefaultGetterName
 import ProtoTypes._
 import Inferencing._
 import transform.TypeUtils._
-import Nullables.{postProcessByNameArgs, given}
+import Nullables.{postProcessByNameArgs, given _}
 
 import collection.mutable
 import config.Printers.{overload, typr, unapp}

compiler/src/dotty/tools/dotc/typer/Implicits.scala

@@ -1483,7 +1483,7 @@ trait Implicits { self: Typer =>
           if diff == 0 then
             // Fall back: if both results are extension method applications,
             // compare the extension methods instead of their wrappers.
-            object extMethodApply with
+            object extMethodApply:
               def unapply(t: Tree): Option[Type] = t match
                 case t: Applications.ExtMethodApply => Some(methPart(stripApply(t.app)).tpe)
                 case _ => None

compiler/src/dotty/tools/dotc/typer/ImportSuggestions.scala

@@ -16,7 +16,7 @@ import collection.mutable
 /** This trait defines the method `importSuggestionAddendum` that adds an addendum
  *  to error messages suggesting additional imports.
  */
-trait ImportSuggestions with
+trait ImportSuggestions:
   this: Typer =>
 
   import tpd._
@@ -167,7 +167,7 @@ trait ImportSuggestions with
     def deepTest(ref: TermRef): Boolean =
       System.currentTimeMillis < deadLine
       && {
-        val task = new TimerTask with
+        val task = new TimerTask:
           def run() =
             println(i"Cancelling test of $ref when making suggestions for error in ${ctx.source}")
             ctx.run.isCancelled = true

compiler/src/dotty/tools/dotc/typer/Inliner.scala

@@ -24,7 +24,7 @@ import ErrorReporting.errorTree
 import dotty.tools.dotc.tastyreflect.ReflectionImpl
 import dotty.tools.dotc.util.{SimpleIdentityMap, SimpleIdentitySet, SourceFile, SourcePosition}
 import dotty.tools.dotc.parsing.Parsers.Parser
-import Nullables.given
+import Nullables.{given _}
 
 import collection.mutable
 import reporting.trace

compiler/src/dotty/tools/dotc/typer/Nullables.scala

@@ -370,7 +370,7 @@ object Nullables:
   def assignmentSpans(using Context): Map[Int, List[Span]] =
     import ast.untpd._
 
-    object populate extends UntypedTreeTraverser with
+    object populate extends UntypedTreeTraverser:
 
       /** The name offsets of variables that are tracked */
       var tracked: Map[Int, List[Span]] = Map.empty
@@ -468,7 +468,7 @@ object Nullables:
       if mt.paramInfos.exists(_.isInstanceOf[ExprType]) && !fn.symbol.is(Inline) =>
         app match
           case Apply(fn, args) =>
-            val dropNotNull = new TreeMap with
+            val dropNotNull = new TreeMap:
               override def transform(t: Tree)(using Context) = t match
                 case AssertNotNull(t0) if t0.symbol.is(Mutable) =>
                   nullables.println(i"dropping $t")
@@ -481,7 +481,7 @@ object Nullables:
                   t
                 case _ => super.transform(t)
 
-            object retyper extends ReTyper with
+            object retyper extends ReTyper:
               override def typedUnadapted(t: untpd.Tree, pt: Type, locked: TypeVars)(implicit ctx: Context): Tree = t match
                 case t: ValDef if !t.symbol.is(Lazy) => super.typedUnadapted(t, pt, locked)
                 case t: MemberDef => promote(t)

compiler/src/dotty/tools/dotc/typer/ProtoTypes.scala

@@ -115,11 +115,11 @@ object ProtoTypes {
   }
 
   /** A class marking ignored prototypes that can be revealed by `deepenProto` */
-  case class IgnoredProto(ignored: Type) extends UncachedGroundType with MatchAlways with
+  case class IgnoredProto(ignored: Type) extends UncachedGroundType with MatchAlways:
     override def revealIgnored = ignored
     override def deepenProto(implicit ctx: Context): Type = ignored
 
-  object IgnoredProto with
+  object IgnoredProto:
     def apply(ignored: Type): IgnoredProto = ignored match
       case ignored: IgnoredProto => ignored
       case _ => new IgnoredProto(ignored)

compiler/src/dotty/tools/dotc/typer/Typer.scala

@@ -40,7 +40,7 @@ import dotty.tools.dotc.transform.{PCPCheckAndHeal, Staging, TreeMapWithStages}
 import transform.SymUtils._
 import transform.TypeUtils._
 import reporting.trace
-import Nullables.{NotNullInfo, given}
+import Nullables.{NotNullInfo, given _}
 import NullOpsDecorator._
 
 object Typer {

compiler/test/dotty/tools/dotc/semanticdb/SemanticdbTests.scala

@@ -19,14 +19,14 @@ import org.junit.experimental.categories.Category
 
 import dotty.BootstrappedOnlyTests
 import dotty.tools.dotc.Main
-import dotty.tools.dotc.semanticdb.Scala3.given
+import dotty.tools.dotc.semanticdb.Scala3.{given _}
 import dotty.tools.dotc.util.SourceFile
 
 @main def updateExpect =
   SemanticdbTests().runExpectTest(updateExpectFiles = true)
 
 @Category(Array(classOf[BootstrappedOnlyTests]))
-class SemanticdbTests with
+class SemanticdbTests:
   val javaFile = FileSystems.getDefault.getPathMatcher("glob:**.java")
   val scalaFile = FileSystems.getDefault.getPathMatcher("glob:**.scala")
   val expectFile = FileSystems.getDefault.getPathMatcher("glob:**.expect.scala")