Change 3.1 to future

It's now

    -source future
    -source future-migration

    import language.future
    import language.`future-migration`

instead of

    -source 3.1
    -source 3.1-migration

    import language.`3.1`
    import language.`3.1-migration`

Author: odersky

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

@@ -226,7 +226,7 @@ object desugar {
 
     def desugarContextBounds(rhs: Tree): Tree = rhs match
       case ContextBounds(tbounds, cxbounds) =>
-        val iflag = if sourceVersion.isAtLeast(`3.1`) then Given else Implicit
+        val iflag = if sourceVersion.isAtLeast(`future`) then Given else Implicit
         evidenceParamBuf ++= makeImplicitParameters(
           cxbounds, iflag, forPrimaryConstructor = isPrimaryConstructor)
         tbounds

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

@@ -169,7 +169,7 @@ object untpd extends Trees.Instance[Untyped] with UntypedTreeInfo {
   enum GenCheckMode {
     case Ignore       // neither filter nor check since filtering was done before
     case Check        // check that pattern is irrefutable
-    case FilterNow    // filter out non-matching elements since we are not yet in 3.1
+    case FilterNow    // filter out non-matching elements since we are not yet in 3.x
     case FilterAlways // filter out non-matching elements since pattern is prefixed by `case`
   }
 

compiler/src/dotty/tools/dotc/config/ScalaSettings.scala

@@ -95,7 +95,7 @@ class ScalaSettings extends Settings.SettingGroup with CommonScalaSettings {
   val feature: Setting[Boolean] = BooleanSetting("-feature", "Emit warning and location for usages of features that should be imported explicitly.", aliases = List("--feature"))
   val help: Setting[Boolean] = BooleanSetting("-help", "Print a synopsis of standard options.", aliases = List("--help"))
   val release: Setting[String] = ChoiceSetting("-release", "release", "Compile code with classes specific to the given version of the Java platform available on the classpath and emit bytecode for this version.", supportedReleaseVersions, "", aliases = List("--release"))
-  val source: Setting[String] = ChoiceSetting("-source", "source version", "source version", List("3.0", "3.1", "3.0-migration", "3.1-migration"), "3.0", aliases = List("--source"))
+  val source: Setting[String] = ChoiceSetting("-source", "source version", "source version", List("3.0", "future", "3.0-migration", "future-migration"), "3.0", aliases = List("--source"))
   val scalajs: Setting[Boolean] = BooleanSetting("-scalajs", "Compile in Scala.js mode (requires scalajs-library.jar on the classpath).", aliases = List("--scalajs"))
   val unchecked: Setting[Boolean] = BooleanSetting("-unchecked", "Enable additional warnings where generated code depends on assumptions.", aliases = List("--unchecked"))
   val uniqid: Setting[Boolean] = BooleanSetting("-uniqid", "Uniquely tag all identifiers in debugging output.", aliases = List("--unique-id"))

compiler/src/dotty/tools/dotc/config/SourceVersion.scala

@@ -9,7 +9,7 @@ import core.Decorators.{_, given}
 import util.Property
 
 enum SourceVersion:
-  case `3.0-migration`, `3.0`, `3.1-migration`, `3.1`
+  case `3.0-migration`, `3.0`, `future-migration`, `future`
 
   val isMigrating: Boolean = toString.endsWith("-migration")
 

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

@@ -6,7 +6,7 @@ import Contexts._, Types._, Symbols._, Names._, Flags._
 import Denotations.SingleDenotation
 import Decorators._
 import collection.mutable
-import config.SourceVersion.`3.1`
+import config.SourceVersion.future
 import config.Feature.sourceVersion
 
 /** Realizability status */
@@ -202,8 +202,8 @@ class CheckRealizable(using Context) {
           realizability(fld.info).mapError(r => new HasProblemField(fld, r))
         }
       }
-    if sourceVersion.isAtLeast(`3.1`) then
-      // check fields only from version 3.1.
+    if sourceVersion.isAtLeast(future) then
+      // check fields only from version 3.x.
       // Reason: An embedded field could well be nullable, which means it
       // should not be part of a path and need not be checked; but we cannot recognize
       // this situation until we have a typesystem that tracks nullability.

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

@@ -946,7 +946,7 @@ object SymDenotations {
       is(Macro, butNot = Inline) && is(Erased)
       // Consider the macros of StringContext as plain Scala 2 macros when
       // compiling the standard library with Dotty.
-      // This should be removed on Scala 3.1
+      // This should be removed on Scala 3.x
       && owner.ne(defn.StringContextClass)
 
     /** An erased value or an erased inline method or field */

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

@@ -1563,7 +1563,7 @@ object Parsers {
         if in.token == LBRACE || in.token == INDENT then
           t
         else
-          if sourceVersion.isAtLeast(`3.1`) then
+          if sourceVersion.isAtLeast(future) then
             deprecationWarning(DeprecatedWithOperator(), withOffset)
           atSpan(startOffset(t)) { makeAndType(t, withType()) }
       else t
@@ -1613,7 +1613,7 @@ object Parsers {
       if isSimpleLiteral then
         SingletonTypeTree(simpleLiteral())
       else if in.token == USCORE then
-        if sourceVersion.isAtLeast(`3.1`) then
+        if sourceVersion.isAtLeast(future) then
           deprecationWarning(em"`_` is deprecated for wildcard arguments of types: use `?` instead")
           patch(source, Span(in.offset, in.offset + 1), "?")
         val start = in.skipToken()
@@ -2080,11 +2080,11 @@ object Parsers {
           val isVarargSplice = location.inArgs && followingIsVararg()
           in.nextToken()
           if isVarargSplice then
-            if sourceVersion.isAtLeast(`3.1`) then
+            if sourceVersion.isAtLeast(future) then
               report.errorOrMigrationWarning(
-                em"The syntax `x: _*` is no longer supported for vararg splices; use `x*` instead${rewriteNotice("3.1")}",
+                em"The syntax `x: _*` is no longer supported for vararg splices; use `x*` instead${rewriteNotice("future")}",
                 in.sourcePos(uscoreStart))
-            if sourceVersion == `3.1-migration` then
+            if sourceVersion == `future-migration` then
               patch(source, Span(t.span.end, in.lastOffset), " *")
           else if opStack.nonEmpty then
             report.errorOrMigrationWarning(
@@ -2158,15 +2158,15 @@ object Parsers {
         val name = bindingName()
         val t =
           if (in.token == COLON && location == Location.InBlock) {
-            if sourceVersion.isAtLeast(`3.1`) then
+            if sourceVersion.isAtLeast(future) then
                 // Don't error in non-strict mode, as the alternative syntax "implicit (x: T) => ... "
                 // is not supported by Scala2.x
               report.errorOrMigrationWarning(
-                s"This syntax is no longer supported; parameter needs to be enclosed in (...)${rewriteNotice("3.1")}",
+                s"This syntax is no longer supported; parameter needs to be enclosed in (...)${rewriteNotice("future")}",
                 source.atSpan(Span(start, in.lastOffset)))
             in.nextToken()
             val t = infixType()
-            if (sourceVersion == `3.1-migration`) {
+            if (sourceVersion == `future-migration`) {
               patch(source, Span(start), "(")
               patch(source, Span(in.lastOffset), ")")
             }
@@ -2482,7 +2482,7 @@ object Parsers {
       atSpan(startOffset(pat), accept(LARROW)) {
         val checkMode =
           if (casePat) GenCheckMode.FilterAlways
-          else if sourceVersion.isAtLeast(`3.1`) then GenCheckMode.Check
+          else if sourceVersion.isAtLeast(future) then GenCheckMode.Check
           else GenCheckMode.FilterNow  // filter for now, to keep backwards compat
         GenFrom(pat, subExpr(), checkMode)
       }
@@ -2655,7 +2655,7 @@ object Parsers {
         p
 
     private def warnStarMigration(p: Tree) =
-      if sourceVersion.isAtLeast(`3.1`) then
+      if sourceVersion.isAtLeast(future) then
         report.errorOrMigrationWarning(
           em"The syntax `x: _*` is no longer supported for vararg splices; use `x*` instead",
           in.sourcePos(startOffset(p)))
@@ -2790,8 +2790,8 @@ object Parsers {
           syntaxError(DuplicatePrivateProtectedQualifier())
         inBrackets {
           if in.token == THIS then
-            if sourceVersion.isAtLeast(`3.1`) then
-              deprecationWarning("The [this] qualifier is deprecated in Scala 3.1; it should be dropped.")
+            if sourceVersion.isAtLeast(future) then
+              deprecationWarning("The [this] qualifier will be deprecated in the future; it should be dropped.")
             in.nextToken()
             mods | Local
           else mods.withPrivateWithin(ident().toTypeName)
@@ -3202,7 +3202,7 @@ object Parsers {
     /** PatDef  ::=  ids [‘:’ Type] ‘=’ Expr
      *            |  Pattern2 [‘:’ Type] ‘=’ Expr
      *  VarDef  ::=  PatDef
-     *            | id {`,' id} `:' Type `=' `_' (deprecated in 3.1)
+     *            | id {`,' id} `:' Type `=' `_' (deprecated in 3.x)
      *  ValDcl  ::=  id {`,' id} `:' Type
      *  VarDcl  ::=  id {`,' id} `:' Type
      */
@@ -3229,7 +3229,7 @@ object Parsers {
           subExpr() match
             case rhs0 @ Ident(name) if placeholderParams.nonEmpty && name == placeholderParams.head.name
                 && !tpt.isEmpty && mods.is(Mutable) && lhs.forall(_.isInstanceOf[Ident]) =>
-              if sourceVersion.isAtLeast(`3.1`) then
+              if sourceVersion.isAtLeast(future) then
                 deprecationWarning(
                   em"""`= _` has been deprecated; use `= uninitialized` instead.
                       |`uninitialized` can be imported with `scala.compiletime.uninitialized`.""", rhsOffset)

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

@@ -89,7 +89,7 @@ class NonLocalReturns extends MiniPhase {
 
   override def transformReturn(tree: Return)(using Context): Tree =
     if isNonLocalReturn(tree) then
-      if sourceVersion.isAtLeast(`3.1`) then
+      if sourceVersion.isAtLeast(future) then
         report.errorOrMigrationWarning("Non local returns are no longer supported; use scala.util.control.NonLocalReturns instead", tree.srcPos)
       nonLocalReturnThrow(tree.expr, tree.from.symbol).withSpan(tree.span)
     else tree

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

@@ -159,7 +159,7 @@ class PostTyper extends MacroTransform with IdentityDenotTransformer { thisPhase
           if sym.isScala2Macro && !ctx.settings.XignoreScala2Macros.value then
             if !sym.owner.unforcedDecls.exists(p => !p.isScala2Macro && p.name == sym.name && p.signature == sym.signature)
                // Allow scala.reflect.materializeClassTag to be able to compile scala/reflect/package.scala
-               // This should be removed on Scala 3.1
+               // This should be removed on Scala 3.x
                && sym.owner != defn.ReflectPackageClass
             then
               report.error("No Scala 3 implementation found for this Scala 2 macro.", tree.srcPos)

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

@@ -700,7 +700,7 @@ trait Checking {
     def check(pat: Tree, pt: Type): Boolean = (pt <:< pat.tpe) || fail(pat, pt)
 
     def recur(pat: Tree, pt: Type): Boolean =
-      !sourceVersion.isAtLeast(`3.1`) || // only for 3.1 for now since mitigations work only after this PR
+      !sourceVersion.isAtLeast(future) || // only for 3.x for now since mitigations work only after this PR
       pt.hasAnnotation(defn.UncheckedAnnot) || {
         patmatch.println(i"check irrefutable $pat: ${pat.tpe} against $pt")
         pat match {
@@ -844,7 +844,7 @@ trait Checking {
              !meth.isDeclaredInfix &&
              !meth.maybeOwner.is(Scala2x) &&
              !infixOKSinceFollowedBy(tree.right) &&
-             sourceVersion.isAtLeast(`3.1`) =>
+             sourceVersion.isAtLeast(future) =>
             val (kind, alternative) =
               if (ctx.mode.is(Mode.Type))
                 ("type", (n: Name) => s"prefix syntax $n[...]")
@@ -1277,7 +1277,7 @@ trait Checking {
         if stat.isDef then seen += tname
 
   def checkMatchable(tp: Type, pos: SrcPos, pattern: Boolean)(using Context): Unit =
-    if !tp.derivesFrom(defn.MatchableClass) && sourceVersion.isAtLeast(`3.1-migration`) then
+    if !tp.derivesFrom(defn.MatchableClass) && sourceVersion.isAtLeast(`future-migration`) then
       val kind = if pattern then "pattern selector" else "value"
       report.warning(
         em"""${kind} should be an instance of Matchable,

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

@@ -1227,7 +1227,7 @@ class Namer { typer: Typer =>
             else if pclazz.isEffectivelySealed && pclazz.associatedFile != cls.associatedFile then
               if pclazz.is(Sealed) then
                 report.error(UnableToExtendSealedClass(pclazz), cls.srcPos)
-              else if sourceVersion.isAtLeast(`3.1`) then
+              else if sourceVersion.isAtLeast(future) then
                 checkFeature(nme.adhocExtensions,
                   i"Unless $pclazz is declared 'open', its extension in a separate file",
                   cls.topLevelClass,

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

@@ -61,7 +61,7 @@ trait QuotesAndSplices {
         typedQuotePattern(tree, pt, qctx)
       else if tree.quoted.isType then
         val msg = em"Consider using canonical type constructor scala.quoted.Type.of[${tree.quoted}] instead"
-        if sourceVersion.isAtLeast(`3.1-migration`) then report.error(msg, tree.srcPos)
+        if sourceVersion.isAtLeast(`future-migration`) then report.error(msg, tree.srcPos)
         else report.warning(msg, tree.srcPos)
         typedTypeApply(untpd.TypeApply(untpd.ref(defn.QuotedTypeModule_of.termRef), tree.quoted :: Nil), pt)(using quoteContext).select(nme.apply).appliedTo(qctx)
       else
@@ -166,7 +166,7 @@ trait QuotesAndSplices {
     else
       val tree1 = typedSelect(untpd.Select(tree.expr, tpnme.Underlying), pt)(using spliceContext).withSpan(tree.span)
       val msg = em"Consider using canonical type reference ${tree1.tpe} instead"
-      if sourceVersion.isAtLeast(`3.1-migration`) then report.error(msg, tree.srcPos)
+      if sourceVersion.isAtLeast(`future-migration`) then report.error(msg, tree.srcPos)
       else report.warning(msg, tree.srcPos)
       tree1
   }

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

@@ -848,7 +848,7 @@ class Typer extends Namer
       val tag = withTag(defn.TypeTestClass.typeRef.appliedTo(pt, tref))
           .orElse(withTag(defn.ClassTagClass.typeRef.appliedTo(tref)))
           .getOrElse(tree)
-      if tag.symbol.owner == defn.ClassTagClass && config.Feature.sourceVersion.isAtLeast(config.SourceVersion.`3.1`) then
+      if tag.symbol.owner == defn.ClassTagClass && config.Feature.sourceVersion.isAtLeast(config.SourceVersion.future) then
         report.warning("Use of `scala.reflect.ClassTag` for type testing may be unsound. Consider using `scala.reflect.TypeTest` instead.", tree.srcPos)
       tag
     case _ => tree
@@ -865,9 +865,9 @@ class Typer extends Namer
      */
     val arg1 = pt match {
       case AppliedType(a, typ :: Nil) if ctx.isJava && a.isRef(defn.ArrayClass) =>
-        tryAlternatively { typed(tree.arg, pt) } { 
+        tryAlternatively { typed(tree.arg, pt) } {
             val elemTp = untpd.TypedSplice(TypeTree(typ))
-            typed(untpd.JavaSeqLiteral(tree.arg :: Nil, elemTp), pt) 
+            typed(untpd.JavaSeqLiteral(tree.arg :: Nil, elemTp), pt)
         }
       case _ => typed(tree.arg, pt)
     }
@@ -1442,7 +1442,7 @@ class Typer extends Namer
             tree.selector.removeAttachment(desugar.CheckIrrefutable) match {
               case Some(checkMode) =>
                 val isPatDef = checkMode == desugar.MatchCheck.IrrefutablePatDef
-                if (!checkIrrefutable(sel, pat, isPatDef) && sourceVersion == `3.1-migration`)
+                if (!checkIrrefutable(sel, pat, isPatDef) && sourceVersion == `future-migration`)
                   if (isPatDef) patch(Span(tree.selector.span.end), ": @unchecked")
                   else patch(Span(pat.span.start), "case ")
 
@@ -2428,7 +2428,7 @@ class Typer extends Namer
         }
     }
     nestedCtx.typerState.commit()
-    if sourceVersion.isAtLeast(`3.1`) then
+    if sourceVersion.isAtLeast(future) then
       lazy val (prefix, suffix) = res match {
         case Block(mdef @ DefDef(_, vparams :: Nil, _, _) :: Nil, _: Closure) =>
           val arity = vparams.length
@@ -2440,7 +2440,7 @@ class Typer extends Namer
         if ((prefix ++ suffix).isEmpty) "simply leave out the trailing ` _`"
         else s"use `$prefix<function>$suffix` instead"
       report.errorOrMigrationWarning(i"""The syntax `<function> _` is no longer supported;
-                                     |you can $remedy""", tree.srcPos, `3.1`)
+                                     |you can $remedy""", tree.srcPos, future)
       if sourceVersion.isMigrating then
         patch(Span(tree.span.start), prefix)
         patch(Span(qual.span.end, tree.span.end), suffix)
@@ -3148,8 +3148,8 @@ class Typer extends Namer
           def isContextBoundParams = wtp.stripPoly match
             case MethodType(EvidenceParamName(_) :: _) => true
             case _ => false
-          if sourceVersion == `3.1-migration` && isContextBoundParams
-          then // Under 3.1-migration, don't infer implicit arguments yet for parameters
+          if sourceVersion == `future-migration` && isContextBoundParams
+          then // Under future-migration, don't infer implicit arguments yet for parameters
                // coming from context bounds. Issue a warning instead and offer a patch.
             report.migrationWarning(
               em"""Context bounds will map to context parameters.