Drop old syntax styles for givens

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

@@ -933,7 +933,7 @@ object desugar {
 
   /** Invent a name for an anonympus given of type or template `impl`. */
   def inventGivenName(impl: Tree)(implicit ctx: Context): SimpleName =
-    avoidIllegalChars(s"${inventName(impl)}_given".toTermName.asSimpleName)
+    avoidIllegalChars(s"given_${inventName(impl)}".toTermName.asSimpleName)
 
   /** The normalized name of `mdef`. This means
    *   1. Check that the name does not redefine a Scala core class.

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

@@ -2518,7 +2518,6 @@ object Parsers {
       case ABSTRACT    => Mod.Abstract()
       case FINAL       => Mod.Final()
       case IMPLICIT    => Mod.Implicit()
-      case IMPLIED     => Mod.Given()
       case GIVEN       => Mod.Given()
       case ERASED      => Mod.Erased()
       case LAZY        => Mod.Lazy()
@@ -2622,10 +2621,10 @@ object Parsers {
      *  FunTypeMods ::=  { ‘erased’ | ‘given’}
      */
     val closureMods: BitSet =
-      if allowOldGiven then BitSet(GIVEN, IMPLIED, IMPLICIT, ERASED)
+      if allowOldGiven then BitSet(GIVEN, IMPLICIT, ERASED)
       else BitSet(IMPLICIT, ERASED)
 
-    val funTypeMods: BitSet = BitSet(IMPLIED, ERASED)
+    val funTypeMods: BitSet = BitSet(ERASED)
 
     val funTypeArgMods: BitSet = BitSet(GIVEN, ERASED)
 
@@ -2923,7 +2922,7 @@ object Parsers {
      */
     def importClause(leading: Token, mkTree: ImportConstr): List[Tree] = {
       val offset = accept(leading)
-      val importGiven = allowOldGiven && in.token == IMPLIED || in.token == GIVEN
+      val importGiven = allowOldGiven && in.token == GIVEN
       if (importGiven) in.nextToken()
       commaSeparated(importExpr(importGiven, mkTree)) match {
         case t :: rest =>
@@ -3267,8 +3266,8 @@ object Parsers {
           objectDef(start, posMods(start, mods | Case | Module))
         case ENUM =>
           enumDef(start, posMods(start, mods | Enum))
-        case IMPLIED | GIVEN =>
-          instanceDef(in.token == GIVEN, start, mods, atSpan(in.skipToken()) { Mod.Given() })
+        case GIVEN =>
+          instanceDef(start, mods, atSpan(in.skipToken()) { Mod.Given() })
         case _ =>
           syntaxErrorOrIncomplete(ExpectedStartOfTopLevelDefinition())
           EmptyTree
@@ -3384,7 +3383,7 @@ object Parsers {
      *  GivenSig       ::=  [id] [DefTypeParamClause] {GivenParamClause}
      *  ExtParamClause ::=  [DefTypeParamClause] DefParamClause {GivenParamClause}
      */
-    def instanceDef(newStyle: Boolean, start: Offset, mods: Modifiers, instanceMod: Mod) = atSpan(start, nameStart) {
+    def instanceDef(start: Offset, mods: Modifiers, instanceMod: Mod) = atSpan(start, nameStart) {
       var mods1 = addMod(mods, instanceMod)
       val hasGivenSig = followingIsGivenSig()
       val name = if isIdent && hasGivenSig then ident() else EmptyTermName
@@ -3409,7 +3408,7 @@ object Parsers {
         parseParams(isExtension = !hasGivenSig)
         var oldSyntax = false
         val parents =
-          if allowOldGiven && (!newStyle && in.token == FOR || isIdent(nme.as)) then
+          if allowOldGiven && isIdent(nme.as) then
             oldSyntax = true
             // for the moment, accept both `delegate for` and `given as`
             in.nextToken()
@@ -3734,12 +3733,12 @@ object Parsers {
         setLastStatOffset()
         if (in.token == IMPORT)
           stats ++= importClause(IMPORT, Import)
-        else if (in.token == IMPLIED || in.token == GIVEN) {
+        else if (in.token == GIVEN) {
           val start = in.offset
           val mods = modifiers(closureMods)
           mods.mods match {
             case givenMod :: Nil if !isBindingIntro =>
-              stats += instanceDef(true, start, EmptyModifiers, Mod.Given().withSpan(givenMod.span))
+              stats += instanceDef(start, EmptyModifiers, Mod.Given().withSpan(givenMod.span))
             case _ =>
               stats += implicitClosure(in.offset, Location.InBlock, mods)
           }

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

@@ -182,10 +182,9 @@ object Tokens extends TokensCommon {
   final val FORSOME = 61;          enter(FORSOME, "forSome") // TODO: deprecate
   final val ENUM = 62;             enter(ENUM, "enum")
   final val ERASED = 63;           enter(ERASED, "erased")
-  final val IMPLIED = 64;          enter(IMPLIED, "delegate")
-  final val GIVEN = 65;            enter(GIVEN, "given")
-  final val EXPORT = 66;           enter(EXPORT, "export")
-  final val MACRO = 67;            enter(MACRO, "macro") // TODO: remove
+  final val GIVEN = 64;            enter(GIVEN, "given")
+  final val EXPORT = 65;           enter(EXPORT, "export")
+  final val MACRO = 66;            enter(MACRO, "macro") // TODO: remove
 
   /** special symbols */
   final val NEWLINE = 78;          enter(NEWLINE, "end of statement", "new line")
@@ -221,14 +220,14 @@ object Tokens extends TokensCommon {
     USCORE, NULL, THIS, SUPER, TRUE, FALSE, RETURN, QUOTEID, XMLSTART)
 
   final val canStartExpressionTokens: TokenSet = atomicExprTokens | BitSet(
-    LBRACE, LPAREN, INDENT, QUOTE, IF, DO, WHILE, FOR, NEW, TRY, THROW, GIVEN)
+    LBRACE, LPAREN, INDENT, QUOTE, IF, DO, WHILE, FOR, NEW, TRY, THROW)
 
   final val canStartTypeTokens: TokenSet = literalTokens | identifierTokens | BitSet(
     THIS, SUPER, USCORE, LPAREN, AT)
 
   final val templateIntroTokens: TokenSet = BitSet(CLASS, TRAIT, OBJECT, ENUM, CASECLASS, CASEOBJECT)
 
-  final val dclIntroTokens: TokenSet = BitSet(DEF, VAL, VAR, TYPE, IMPLIED, GIVEN)
+  final val dclIntroTokens: TokenSet = BitSet(DEF, VAL, VAR, TYPE, GIVEN)
 
   final val defIntroTokens: TokenSet = templateIntroTokens | dclIntroTokens
 
@@ -245,8 +244,6 @@ object Tokens extends TokensCommon {
 
   final val modifierFollowers = modifierTokens | defIntroTokens
 
-  final val paramIntroTokens: TokenSet = modifierTokens | identifierTokens | BitSet(AT, VAL, VAR, IMPLICIT)
-
   /** Is token only legal as start of statement (eof also included)? */
   final val mustStartStatTokens: TokenSet = defIntroTokens | modifierTokens | BitSet(IMPORT, EXPORT, PACKAGE)
 
@@ -268,7 +265,7 @@ object Tokens extends TokensCommon {
 
   final val canStartIndentTokens: BitSet =
     statCtdTokens | BitSet(COLONEOL, EQUALS, ARROW, LARROW, WHILE, TRY, FOR)
-      // `if` is excluded because it often comes after `else` which makes for awkward indentation rules
+      // `if` is excluded because it often comes after `else` which makes for awkward indentation rules  TODO: try to do without the exception
 
   /** Faced with the choice between a type and a formal parameter, the following
    *  tokens determine it's a formal parameter.
@@ -285,7 +282,7 @@ object Tokens extends TokensCommon {
   final val noIndentAfterConditionTokens = BitSet(THEN, DO)
   final val noIndentAfterEnumeratorTokens = BitSet(YIELD, DO)
 
-  final val scala3keywords = BitSet(ENUM, ERASED, GIVEN, IMPLIED)
+  final val scala3keywords = BitSet(ENUM, ERASED, GIVEN)
 
   final val softModifierNames = Set(nme.inline, nme.opaque)
 }

compiler/test/dotty/tools/repl/ReplCompilerTests.scala

@@ -132,7 +132,7 @@ class ReplCompilerTests extends ReplTest {
     fromInitialState { implicit state => run("given as Int = 10") }
     .andThen         { implicit state =>
       assertEquals(
-        "def Int_given: Int",
+        "def given_Int: Int",
         storedOutput().trim
       )
       run("implicitly[Int]")

docs/docs/reference/contextual-new/relationship-implicits.md

@@ -43,7 +43,7 @@ Given instances can be mapped to combinations of implicit objects, classes and i
     would map to
     ```scala
       final implicit lazy val global: ExecutionContext = new ForkJoinContext()
-      final implicit def Context_given = ctx
+      final implicit def given_Context = ctx
     ```
 
 ### Anonymous Given Instances

tests/new/test.scala

@@ -4,7 +4,6 @@ trait T {
   type U = (given Int) => Int
   type V = (given Int) => Int
 
-  val u = delegate (x: Int) => x
   val v = given (x: Int) => x
   val w = (given x: Int) => x
   val w2: V = (given x) => x

tests/pos/i6997b.scala

@@ -1,7 +1,6 @@
 package playground
 
-import scala.quoted._, scala.quoted.matching._
-import delegate scala.quoted._
+import scala.quoted.{_, given}, scala.quoted.matching._
 
 inline def mcr(x: => Any): Any = ${mcrImpl('x)}
 

tests/pos/reference/delegates.scala

@@ -226,13 +226,13 @@ object Implicits extends Common {
   }
   implicit def ListOrd[T: Ord]: Ord[List[T]] = new ListOrd[T]
 
-  class Convertible_List_List_given[From, To](implicit c: Convertible[From, To])
+  class given_Convertible_List_List[From, To](implicit c: Convertible[From, To])
   extends Convertible[List[From], List[To]] {
     def (x: List[From]) convert: List[To] = x.map(c.convert)
   }
-  implicit def Convertible_List_List_given[From, To](implicit c: Convertible[From, To])
+  implicit def given_Convertible_List_List[From, To](implicit c: Convertible[From, To])
     : Convertible[List[From], List[To]] =
-    new Convertible_List_List_given[From, To]
+    new given_Convertible_List_List[From, To]
 
   def maximum[T](xs: List[T])
                 (implicit cmp: Ord[T]): T =