Drop other aspects of old extension syntax

Author: odersky

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

@@ -596,7 +596,7 @@ object Contexts {
     def setDebug: this.type = setSetting(base.settings.Ydebug, true)
   }
 
-  given ops: (c: Context)
+  given ops: extension (c: Context) with
     def addNotNullInfo(info: NotNullInfo) =
       c.withNotNullInfos(c.notNullInfos.extendWith(info))
 

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

@@ -3362,27 +3362,6 @@ object Parsers {
       Template(constr, parents, Nil, EmptyValDef, Nil)
     }
 
-    /** Check that `vparamss` represents a legal collective parameter list for a given extension
-     */
-    def checkExtensionParams(start: Offset, vparamss: List[List[ValDef]]): Unit = vparamss match
-      case (vparam :: Nil) :: vparamss1 if !vparam.mods.is(Given) =>
-        vparamss1.foreach(_.foreach(vparam =>
-          if !vparam.mods.is(Given) then
-            syntaxError(em"follow-on parameter in extension clause must be `given`", vparam.span)))
-      case _ =>
-        syntaxError(em"extension clause must start with a single regular parameter", start)
-
-    def checkExtensionMethod(tparams: List[Tree], stat: Tree): Unit = stat match {
-      case stat: DefDef =>
-        if stat.mods.is(Extension) then
-          syntaxError(i"no extension method allowed here since leading parameter was already given", stat.span)
-        else if tparams.nonEmpty && stat.tparams.nonEmpty then
-          syntaxError(i"extension method cannot have type parameters since some were already given previously",
-            stat.tparams.head.span)
-      case stat =>
-        syntaxError(i"extension clause can only define methods", stat.span)
-    }
-
     /** GivenDef       ::=  [GivenSig (‘:’ | <:)] Type ‘=’ Expr
      *                   |  [GivenSig ‘:’] ConstrApps [[‘with’] TemplateBody]
      *                   |  [id ‘:’] ‘extension’ ExtParamClause {GivenParamClause} ExtMethods
@@ -3409,45 +3388,32 @@ object Parsers {
           possibleTemplateStart()
           val templ = templateBodyOpt(
             makeConstructor(tparams, extParams :: givenParamss), Nil, Nil)
-          templ.body.foreach(checkExtensionMethod(tparams, _))
+          templ.body.foreach {
+            case stat: DefDef =>
+              if stat.mods.is(Extension) then
+                syntaxError(i"no extension method allowed here since leading parameter was already given", stat.span)
+              else if tparams.nonEmpty && stat.tparams.nonEmpty then
+                syntaxError(i"extension method cannot have type parameters since some were already given previously",
+                  stat.tparams.head.span)
+            case stat =>
+              syntaxError(i"extension clause can only define methods", stat.span)
+          }
           ModuleDef(name, templ)
         else
-          var tparams: List[TypeDef] = Nil
-          var vparamss: List[List[ValDef]] = Nil
-          var hasExtensionParams = false
-
-          def parseParams(isExtension: Boolean): Unit =
-            if isExtension && (in.token == LBRACKET || in.token == LPAREN) then
-              hasExtensionParams = true
-              if tparams.nonEmpty || vparamss.nonEmpty then
-                syntaxError(i"cannot have parameters before and after `:` in extension")
-            if in.token == LBRACKET then
-              tparams = typeParamClause(ParamOwner.Def)
+          val tparams: List[TypeDef] = typeParamClauseOpt(ParamOwner.Def)
+          val vparamss: List[List[ValDef]] =
             if in.token == LPAREN && followingIsParamOrGivenType() then
-              val paramsStart = in.offset
-              vparamss = paramClauses(givenOnly = !isExtension)
-              if isExtension then
-                checkExtensionParams(paramsStart, vparamss)
-
-          parseParams(isExtension = false)
+              paramClauses(givenOnly = true)
+            else Nil
           val parents =
-            if in.token == COLON then
-              in.nextToken()
-              if in.token == LBRACKET
-                 || in.token == LPAREN && followingIsParamOrGivenType()
-              then
-                parseParams(isExtension = true)
-                Nil
-              else
-                constrApps(commaOK = true, templateCanFollow = true)
-            else if in.token == SUBTYPE then
+            if in.token == SUBTYPE then
               if !mods.is(Inline) then
                 syntaxError("`<:' is only allowed for given with `inline' modifier")
               in.nextToken()
               TypeBoundsTree(EmptyTree, toplevelTyp()) :: Nil
-            else if name.isEmpty && !hasExtensionParams then
+            else
+              if in.token == COLON then in.nextToken()
               constrApps(commaOK = true, templateCanFollow = true)
-            else Nil
 
           if in.token == EQUALS && parents.length == 1 && parents.head.isType then
             in.nextToken()
@@ -3458,17 +3424,11 @@ object Parsers {
               case TypeBoundsTree(_, _) :: _ => syntaxError("`=' expected")
               case _ =>
             possibleTemplateStart()
-            if hasExtensionParams then
-              in.observeIndented()
-            else
-              tparams = tparams.map(tparam => tparam.withMods(tparam.mods | PrivateLocal))
-              vparamss = vparamss.map(_.map(vparam =>
-                vparam.withMods(vparam.mods &~ Param | ParamAccessor | PrivateLocal)))
-            val templ = templateBodyOpt(makeConstructor(tparams, vparamss), parents, Nil)
-            if hasExtensionParams then
-              templ.body.foreach(checkExtensionMethod(tparams, _))
-              ModuleDef(name, templ)
-            else if tparams.isEmpty && vparamss.isEmpty then ModuleDef(name, templ)
+            val tparams1 = tparams.map(tparam => tparam.withMods(tparam.mods | PrivateLocal))
+            val vparamss1 = vparamss.map(_.map(vparam =>
+              vparam.withMods(vparam.mods &~ Param | ParamAccessor | PrivateLocal)))
+            val templ = templateBodyOpt(makeConstructor(tparams1, vparamss1), parents, Nil)
+            if tparams.isEmpty && vparamss.isEmpty then ModuleDef(name, templ)
             else TypeDef(name.toTypeName, templ)
       }
       finalizeDef(gdef, mods1, start)

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

@@ -137,7 +137,7 @@ object Nullables with
     // TODO: Add constant pattern if the constant type is not nullable
     case _ => false
 
-  given notNullInfoOps: (infos: List[NotNullInfo])
+  given notNullInfoOps: extension (infos: List[NotNullInfo]) with
 
     /** Do the current not-null infos imply that `ref` is not null?
      *  Not-null infos are as a history where earlier assertions and retractions replace
@@ -161,7 +161,7 @@ object Nullables with
       then infos
       else info :: infos
 
-  given treeOps: (tree: Tree)
+  given treeOps: extension (tree: Tree) with
 
     /* The `tree` with added nullability attachment */
     def withNotNullInfo(info: NotNullInfo): tree.type =
@@ -251,7 +251,7 @@ object Nullables with
           tree.computeNullable()
       }.traverse(tree)
 
-  given assignOps: (tree: Assign)
+  given assignOps: extension (tree: Assign) with
     def computeAssignNullable()(given Context): tree.type = tree.lhs match
       case TrackedRef(ref) =>
         tree.withNotNullInfo(NotNullInfo(Set(), Set(ref))) // TODO: refine with nullability type info

library/src/scala/tasty/reflect/CommentOps.scala

@@ -2,7 +2,7 @@ package scala.tasty.reflect
 
 trait CommentOps extends Core {
 
-  given CommentOps: (self: Comment) {
+  given CommentOps: extension (self: Comment) {
 
     /** Raw comment string */
     def raw: String = internal.Comment_raw(self)

library/src/scala/tasty/reflect/ConstantOps.scala

@@ -3,7 +3,7 @@ package reflect
 
 trait ConstantOps extends Core {
 
-  given ConstantOps: (const: Constant) {
+  given ConstantOps: extension (const: Constant) {
     def value: Any = internal.Constant_value(const)
   }
 

library/src/scala/tasty/reflect/ContextOps.scala

@@ -3,7 +3,7 @@ package reflect
 
 trait ContextOps extends Core {
 
-  given ContextOps: (self: Context) {
+  given ContextOps: extension (self: Context) {
     /** Returns the owner of the context */
     def owner: Symbol = internal.Context_owner(self)
 

library/src/scala/tasty/reflect/FlagsOps.scala

@@ -2,7 +2,7 @@ package scala.tasty.reflect
 
 trait FlagsOps extends Core {
 
-  given FlagsOps: (self: Flags) {
+  given FlagsOps: extension (self: Flags) {
 
     /** Is the given flag set a subset of this flag sets */
     def is(that: Flags): Boolean = internal.Flags_is(self)(that)

library/src/scala/tasty/reflect/IdOps.scala

@@ -3,7 +3,7 @@ package reflect
 
 trait IdOps extends Core {
 
-  given IsOps: (id: Id) {
+  given IdOps: extension (id: Id) {
 
     /** Position in the source code */
     def pos(given ctx: Context): Position = internal.Id_pos(id)

library/src/scala/tasty/reflect/ImplicitsOps.scala

@@ -11,7 +11,7 @@ trait ImplicitsOps extends Core {
     @deprecated("Use _: ImplicitSearchSuccess", "")
     def unapply(isr: ImplicitSearchSuccess)(given ctx: Context): Option[ImplicitSearchSuccess] = Some(isr)
 
-  given SuccessOps: (self: ImplicitSearchSuccess) {
+  given successOps: extension (self: ImplicitSearchSuccess) {
     def tree(given ctx: Context): Term = internal.ImplicitSearchSuccess_tree(self)
   }
 
@@ -21,7 +21,7 @@ trait ImplicitsOps extends Core {
     @deprecated("Use _: ImplicitSearchFailure", "")
     def unapply(isr: ImplicitSearchFailure)(given ctx: Context): Option[ImplicitSearchFailure] = Some(isr)
 
-  given FailureOps: (self: ImplicitSearchFailure) {
+  given failureOps: extension (self: ImplicitSearchFailure) {
     def explanation(given ctx: Context): String = internal.ImplicitSearchFailure_explanation(self)
   }
 

library/src/scala/tasty/reflect/ImportSelectorOps.scala

@@ -3,7 +3,7 @@ package reflect
 
 trait ImportSelectorOps extends Core {
 
-  given SimpleSelectorOps: (self: SimpleSelector) {
+  given simpleSelectorOps: extension (self: SimpleSelector) {
     def selection(given ctx: Context): Id =
       internal.SimpleSelector_selection(self)
   }
@@ -13,7 +13,7 @@ trait ImportSelectorOps extends Core {
   object SimpleSelector
     def unapply(x: SimpleSelector)(given ctx: Context): Option[Id] = Some(x.selection)
 
-  given RenameSelectorOps: (self: RenameSelector) {
+  given renameSelectorOps: extension (self: RenameSelector) {
     def from(given ctx: Context): Id =
       internal.RenameSelector_from(self)
 
@@ -26,7 +26,7 @@ trait ImportSelectorOps extends Core {
   object RenameSelector
     def unapply(x: RenameSelector)(given ctx: Context): Option[(Id, Id)] = Some((x.from, x.to))
 
-  given OmitSelectorOps: (self: OmitSelector) {
+  given omitSelectorOps: extension (self: OmitSelector) {
     def omitted(given ctx: Context): Id =
       internal.SimpleSelector_omitted(self)
   }

library/src/scala/tasty/reflect/PositionOps.scala

@@ -2,7 +2,7 @@ package scala.tasty.reflect
 
 trait PositionOps extends Core {
 
-  given PositionOps: (pos: Position) {
+  given positionOps: extension (pos: Position) {
 
     /** The start offset in the source file */
     def start: Int = internal.Position_start(pos)
@@ -33,7 +33,7 @@ trait PositionOps extends Core {
 
   }
 
-  given SourceFileOps: (sourceFile: SourceFile) {
+  given sourceFileOps: extension (sourceFile: SourceFile) {
 
     /** Path to this source file */
     def jpath: java.nio.file.Path = internal.SourceFile_jpath(sourceFile)

library/src/scala/tasty/reflect/SignatureOps.scala

@@ -9,7 +9,7 @@ trait SignatureOps extends Core {
       Some((sig.paramSigs, sig.resultSig))
   }
 
-  given SignatureOps: (sig: Signature) {
+  given signatureOps: extension (sig: Signature) {
 
     /** The signatures of the method parameters.
       *

library/src/scala/tasty/reflect/SymbolOps.scala

@@ -14,7 +14,7 @@ trait SymbolOps extends Core { selfSymbolOps: FlagsOps =>
       internal.Symbol_noSymbol
   }
 
-  given SymbolOps: (self: Symbol) {
+  given symbolOps: extension (self: Symbol) {
 
     /** Owner of this symbol. The owner is the symbol in which this symbol is defined */
     def owner(given ctx: Context): Symbol = internal.Symbol_owner(self)