Fewer braces are part of the language from 3.3.x

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

@@ -26,7 +26,6 @@ object Feature:
   val dependent = experimental("dependent")
   val erasedDefinitions = experimental("erasedDefinitions")
   val symbolLiterals = deprecated("symbolLiterals")
-  val fewerBraces = experimental("fewerBraces")
   val saferExceptions = experimental("saferExceptions")
 
   /** Is `feature` enabled by by a command-line setting? The enabling setting is

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

@@ -58,7 +58,7 @@ trait AllScalaSettings extends CommonScalaSettings, PluginSettings, VerboseSetti
   val oldSyntax: Setting[Boolean] = BooleanSetting("-old-syntax", "Require `(...)` around conditions.")
   val indent: Setting[Boolean] = BooleanSetting("-indent", "Together with -rewrite, remove {...} syntax when possible due to significant indentation.")
   val noindent: Setting[Boolean] = BooleanSetting("-no-indent", "Require classical {...} syntax, indentation is not significant.", aliases = List("-noindent"))
-  val YindentColons: Setting[Boolean] = BooleanSetting("-Yindent-colons", "(disabled: use -language:experimental.fewerBraces instead)")
+  val YindentColons: Setting[Boolean] = BooleanSetting("-Yindent-colons", "(disabled: colons can always indent from Scala v3.2.x)")
 
   /* Decompiler settings */
   val printTasty: Setting[Boolean] = BooleanSetting("-print-tasty", "Prints the raw tasty.", aliases = List("--print-tasty"))

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

@@ -757,7 +757,7 @@ object Parsers {
         }
       })
       canRewrite &= (in.isAfterLineEnd || statCtdTokens.contains(in.token)) // test (5)
-      if (canRewrite && (!underColonSyntax || in.fewerBracesEnabled)) {
+      if (canRewrite && !underColonSyntax) {
         val openingPatchStr =
           if !colonRequired then ""
           else if testChar(startOpening - 1, Chars.isOperatorPart(_)) then " :"
@@ -2252,8 +2252,8 @@ object Parsers {
      *                 |  SimpleExpr `.` MatchClause
      *                 |  SimpleExpr (TypeArgs | NamedTypeArgs)
      *                 |  SimpleExpr1 ArgumentExprs
-     *                 |  SimpleExpr1 `:` IndentedExpr                       -- under language.experimental.fewerBraces
-     *                 |  SimpleExpr1 FunParams (‘=>’ | ‘?=>’) IndentedExpr  -- under language.experimental.fewerBraces
+     *                 |  SimpleExpr1 `:` IndentedExpr
+     *                 |  SimpleExpr1 FunParams (‘=>’ | ‘?=>’) IndentedExpr
      *  IndentedExpr  ::=  indent (CaseClauses | Block) outdent
      *  Quoted        ::= ‘'’ ‘{’ Block ‘}’
      *                 |  ‘'’ ‘[’ Type ‘]’
@@ -2322,7 +2322,7 @@ object Parsers {
         case LPAREN if canApply =>
           val app = atSpan(startOffset(t), in.offset) {
             val argExprs @ (args, isUsing) = argumentExprs()
-            if !isUsing && in.isArrow && location != Location.InGuard && in.fewerBracesEnabled then
+            if !isUsing && in.isArrow && location != Location.InGuard then
               val params = convertToParams(Tuple(args))
               if params.forall(_.name != nme.ERROR) then
                 applyToClosure(t, in.offset, params)
@@ -2336,13 +2336,13 @@ object Parsers {
           val app = atSpan(startOffset(t), in.offset) { mkApply(t, argumentExprs()) }
           simpleExprRest(app, location, canApply = true)
         case USCORE =>
-          if in.lookahead.isArrow && location != Location.InGuard && in.fewerBracesEnabled then
+          if in.lookahead.isArrow && location != Location.InGuard then
             val app = applyToClosure(t, in.offset, convertToParams(wildcardIdent()))
             simpleExprRest(app, location, canApply = true)
           else
             atSpan(startOffset(t), in.skipToken()) { PostfixOp(t, Ident(nme.WILDCARD)) }
         case IDENTIFIER
-        if !in.isOperator && in.lookahead.isArrow && location != Location.InGuard && in.fewerBracesEnabled =>
+        if !in.isOperator && in.lookahead.isArrow && location != Location.InGuard =>
           val app = applyToClosure(t, in.offset, convertToParams(termIdent()))
           simpleExprRest(app, location, canApply = true)
         case _ =>

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

@@ -202,15 +202,6 @@ object Scanners {
     def featureEnabled(name: TermName) = Feature.enabled(name)(using languageImportContext)
     def erasedEnabled = featureEnabled(Feature.erasedDefinitions)
 
-    private var fewerBracesEnabledCache = false
-    private var fewerBracesEnabledCtx: Context = NoContext
-
-    def fewerBracesEnabled =
-      if fewerBracesEnabledCtx ne myLanguageImportContext then
-        fewerBracesEnabledCache = featureEnabled(Feature.fewerBraces)
-        fewerBracesEnabledCtx = myLanguageImportContext
-      fewerBracesEnabledCache
-
     /** All doc comments kept by their end position in a `Map`.
       *
       * Note: the map is necessary since the comments are looked up after an
@@ -655,7 +646,7 @@ object Scanners {
         case END =>
           if !isEndMarker then token = IDENTIFIER
         case COLON =>
-          if fewerBracesEnabled then observeColonEOL()
+          observeColonEOL()
         case RBRACE | RPAREN | RBRACKET =>
           closeIndented()
         case EOF =>

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

@@ -243,24 +243,11 @@ class ReplCompilerTests extends ReplTest:
 
   @Test def i14491 =
     initially {
-      run("import language.experimental.fewerBraces")
-    } andThen {
       run("""|val x = Seq(7,8,9).apply:
              |  1
              |""".stripMargin)
       assertEquals("val x: Int = 8", storedOutput().trim)
     }
-    initially {
-      run("""|import language.experimental.fewerBraces
-             |import language.experimental.fewerBraces as _
-             |""".stripMargin)
-    } andThen {
-      run("""|val x = Seq(7,8,9).apply:
-             |  1
-             |""".stripMargin)
-      assert("expected error if fewerBraces is unimported",
-        lines().exists(_.contains("missing arguments for method apply")))
-    }
 
 object ReplCompilerTests:
 

docs/_docs/internals/syntax.md

@@ -254,8 +254,8 @@ SimpleExpr        ::=  SimpleRef
                     |  SimpleExpr ‘.’ MatchClause
                     |  SimpleExpr TypeArgs                                      TypeApply(expr, args)
                     |  SimpleExpr ArgumentExprs                                 Apply(expr, args)
-                    |  SimpleExpr ‘:’ IndentedExpr                              -- under language.experimental.fewerBraces
-                    |  SimpleExpr FunParams (‘=>’ | ‘?=>’) IndentedExpr         -- under language.experimental.fewerBraces
+                    |  SimpleExpr ‘:’ IndentedExpr
+                    |  SimpleExpr FunParams (‘=>’ | ‘?=>’) IndentedExpr
                     |  SimpleExpr ‘_’                                           PostfixOp(expr, _) (to be dropped)
                     |  XmlExpr													                        -- to be dropped
 IndentedExpr      ::=  indent CaseClauses | Block outdent

docs/_docs/reference/experimental/overview.md

@@ -10,7 +10,6 @@ All experimental language features can be found under the `scala.language.experi
 They are enabled by importing the feature or using the `-language` compiler flag.
 
 * [`erasedDefinitions`](./erased-defs.md): Enable support for `erased` modifier.
-* `fewerBraces`: Enable support for using indentation for arguments.
 * [`genericNumberLiterals`](./numeric-literals.md): Enable support for generic number literals.
 * [`namedTypeArguments`](./named-typeargs.md): Enable support for named type arguments
 * [`saferExceptions`](./canthrow.md): Enable support for checked exceptions.

docs/_docs/reference/other-new-features/indentation.md

@@ -416,12 +416,6 @@ The `-indent` option only works on [new-style syntax](./control-syntax.md). So t
 
 Generally, the possible indentation regions coincide with those regions where braces `{...}` are also legal, no matter whether the braces enclose an expression or a set of definitions. There is one exception, though: Arguments to function can be enclosed in braces but they cannot be simply indented instead. Making indentation always significant for function arguments would be too restrictive and fragile.
 
-To allow such arguments to be written without braces, a variant of the indentation scheme is implemented under language import
-```scala
-import language.experimental.fewerBraces
-```
-This variant is more contentious and less stable than the rest of the significant indentation scheme. In this variant, a colon `:` at the end of a line is also one of the possible tokens that opens an indentation region. Examples:
-
 ```scala
 times(10):
   println("ah")

library/src/scala/runtime/stdLibPatches/language.scala

@@ -48,11 +48,6 @@ object language:
     @compileTimeOnly("`erasedDefinitions` can only be used at compile time in import statements")
     object erasedDefinitions
 
-    /** Experimental support for using indentation for arguments
-     */
-    @compileTimeOnly("`fewerBraces` can only be used at compile time in import statements")
-    object fewerBraces
-
     /** Experimental support for typechecked exception capabilities
      *
      *  @see [[https://dotty.epfl.ch/docs/reference/experimental/canthrow]]

project/MiMaFilters.scala

@@ -17,6 +17,8 @@ object MiMaFilters {
     ProblemFilters.exclude[MissingClassProblem]("scala.compiletime.ops.long$"),
     ProblemFilters.exclude[ReversedMissingMethodProblem]("scala.quoted.Quotes#reflectModule#CompilationInfoModule.XmacroSettings"),
     ProblemFilters.exclude[DirectMissingMethodProblem]("scala.quoted.Quotes#reflectModule#CompilationInfoModule.XmacroSettings"),
+    ProblemFilters.exclude[MissingFieldProblem]("scala.runtime.stdLibPatches.language#experimental.fewerBraces"),
+    ProblemFilters.exclude[MissingClassProblem]("scala.runtime.stdLibPatches.language$experimental$fewerBraces$"),
     ProblemFilters.exclude[DirectMissingMethodProblem]("scala.deriving.Mirror.fromProductTyped"),
     ProblemFilters.exclude[DirectMissingMethodProblem]("scala.deriving.Mirror.fromTuple"),
 

tests/neg-custom-args/no-experimental/experimental-imports.scala

@@ -2,44 +2,38 @@ import annotation.experimental
 
 @experimental
 object Object1:
-  import language.experimental.fewerBraces
   import language.experimental.namedTypeArguments
   import language.experimental.genericNumberLiterals
   import language.experimental.erasedDefinitions
   erased def f = 1
 
 object Object2:
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions
   erased def f = 1
 
 @experimental
 object Class1:
-  import language.experimental.fewerBraces
   import language.experimental.namedTypeArguments
   import language.experimental.genericNumberLiterals
   import language.experimental.erasedDefinitions
   erased def f = 1
 
 object Class2:
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions
   erased def f = 1
 
 @experimental
 def fun1 =
-  import language.experimental.fewerBraces
   import language.experimental.namedTypeArguments
   import language.experimental.genericNumberLiterals
   import language.experimental.erasedDefinitions
   erased def f = 1
 
 def fun2 =
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions

tests/neg-custom-args/no-experimental/experimental-nested-imports-2.scala

@@ -1,31 +1,27 @@
 import annotation.experimental
 
 class Class1:
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition
   @experimental def f = 1
   def g = 1
 
 object Object1:
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition
   @experimental def f = 1
   def g = 1
 
 def fun1 =
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition
   @experimental def f = 1
   def g = 1
 
 val value1 =
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition

tests/neg-custom-args/no-experimental/experimental-nested-imports-3.scala

@@ -1,25 +1,21 @@
 import annotation.experimental
 
 class Class1:
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition
 
 object Object1:
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition
 
 def fun1 =
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition
 
 val value1 =
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition

tests/neg-custom-args/no-experimental/experimental-nested-imports.scala

@@ -1,28 +1,24 @@
 import annotation.experimental
 
 class Class1:
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition
   @experimental def f = 1
 
 object Object1:
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition
   @experimental def f = 1
 
 def fun1 =
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition
   @experimental def f = 1
 
 val value1 =
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition

tests/neg-custom-args/no-experimental/experimental-package-imports.scala

@@ -1,7 +1,6 @@
 import annotation.experimental
 
 package foo {
-  import language.experimental.fewerBraces // error
   import language.experimental.namedTypeArguments // error
   import language.experimental.genericNumberLiterals // error
   import language.experimental.erasedDefinitions // ok: only check at erased definition
@@ -13,7 +12,6 @@ package foo {
 
 package foo2 {
   // ok: all definitions are top-level @experimental
-  import language.experimental.fewerBraces
   import language.experimental.namedTypeArguments
   import language.experimental.genericNumberLiterals
   import language.experimental.erasedDefinitions