Make SIP-62 better-fors a stable feature

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

@@ -43,7 +43,7 @@ enum SourceVersion:
   def enablesClauseInterleaving = isAtLeast(`3.6`)
   def enablesNewGivens = isAtLeast(`3.6`)
   def enablesNamedTuples = isAtLeast(`3.7`)
-  def enablesBetterFors(using Context) = isAtLeast(`3.7`) && isPreviewEnabled
+  def enablesBetterFors = isAtLeast(`3.8`)
 
   def requiresNewSyntax = isAtLeast(future)
 

compiler/test/dotty/tools/debug/DebugTests.scala

@@ -19,7 +19,6 @@ class DebugTests:
     CompilationTest.aggregateTests(
       compileFile("tests/debug-custom-args/eval-explicit-nulls.scala", TestConfiguration.explicitNullsOptions),
       compileFilesInDir("tests/debug", TestConfiguration.defaultOptions),
-      compileFilesInDir("tests/debug-preview", TestConfiguration.defaultOptions.and("-preview"))
     ).checkDebug()
 
 object DebugTests extends ParallelTesting:

docs/_docs/reference/preview/better-fors.md → docs/_docs/reference/other-new-features/better-fors.md

@@ -4,7 +4,7 @@ title: "Better fors"
 nightlyOf: https://docs.scala-lang.org/scala3/reference/preview/better-fors.html
 ---
 
-Starting in Scala `3.7` under `-preview` mode, the usability of `for`-comprehensions is improved.
+Starting in Scala `3.8` or under `-preview` mode using Scala `3.7`, the usability of `for`-comprehensions has improved.
 
 The biggest user facing change is the new ability to start `for`-comprehensions with aliases. This means that the following previously invalid code is now valid:
 

docs/_docs/reference/preview/overview.md

@@ -21,5 +21,4 @@ This flag enables the use of all preview language feature in the project.
 
 ## List of available preview features
 
-* [`better-fors`](./better-fors.md): Enables new for-comprehension behaviour under SIP-62 under `-source:3.7` or later
-
+Currently there are no available preview features.

docs/sidebar.yml

@@ -89,6 +89,7 @@ subsection:
           - page: reference/other-new-features/preview-defs.md
           - page: reference/other-new-features/binary-literals.md
           - page: reference/other-new-features/toplevel-definitions.md
+          - page: reference/other-new-features/better-fors.md
       - title: Other Changed Features
         directory: changed-features
         index: reference/changed-features/changed-features.md
@@ -143,8 +144,6 @@ subsection:
       - title: Preview Features
         directory: preview
         index: reference/preview/overview.md
-        subsection:
-          - page: reference/preview/better-fors.md
       - title: Experimental Features
         directory: experimental
         index: reference/experimental/overview.md

presentation-compiler/test/dotty/tools/pc/tests/tokens/SemanticTokensSuite.scala

@@ -6,9 +6,6 @@ import java.nio.file.Path
 import org.junit.Test
 
 class SemanticTokensSuite extends BaseSemanticTokensSuite:
-  // -preview required for `for-comprehension` test
-  override protected def scalacOptions(classpath: Seq[Path]): Seq[String] =
-    super.scalacOptions(classpath) ++ Seq("-preview")
 
   @Test def `class, object, var, val(readonly), method, type, parameter, String(single-line)` =
     check(

tests/debug/eval-in-for-comprehension.check

@@ -8,16 +8,9 @@ eval list(0)
 result 1
 eval x
 result 1
-break Test$ 6 // in main$$anonfun$1$$anonfun$adapted$1
 break Test$ 7 // in main$$anonfun$1$$anonfun$1
 eval x + y
 result 2
-// TODO this line position does not make any sense
-break Test$ 6 // in main$$anonfun$1$$anonfun$1
-break Test$ 7 // in main$$anonfun$1$$anonfun$1
-break Test$ 6 // in main$$anonfun$1$$anonfun$2
-break Test$ 6 // in main$$anonfun$1$$anonfun$2
-break Test$ 7 // in main$$anonfun$1$$anonfun$2
 
 break Test$ 11 // in main$$anonfun$2
 eval x

tests/pos/better-fors-given.scala

@@ -1,5 +1,3 @@
-//> using options -preview
-
 @main def Test: Unit =
   for
     x <- Option(23 -> "abc")

tests/pos/better-fors-i21804.scala

@@ -1,6 +1,3 @@
-//> using options -preview
-// import scala.language.experimental.betterFors
-
 case class Container[A](val value: A) {
   def map[B](f: A => B): Container[B] = Container(f(value))
 }

tests/run/better-fors-map-elim.scala

@@ -1,6 +1,3 @@
-//> using options -preview
-// import scala.language.experimental.betterFors
-
 class myOptionModule(doOnMap: => Unit) {
   sealed trait MyOption[+A] {
     def map[B](f: A => B): MyOption[B] = this match {

tests/run/better-fors.scala

@@ -1,6 +1,3 @@
-//> using options -preview
-// import scala.language.experimental.betterFors
-
 def for1 =
   for {
     a = 1

tests/run/fors.scala

@@ -1,4 +1,3 @@
-//> using options -preview
 //############################################################################
 // for-comprehensions (old and new syntax)
 //############################################################################

tests/semanticdb/expect/ForComprehension.expect.scala

@@ -3,43 +3,43 @@ package example
 class ForComprehension/*<-example::ForComprehension#*/ {
   for {
     a/*<-local0*/ <- List/*->scala::package.List.*/(1)
-    b/*<-local1*//*->local1*/ <- List/*->scala::package.List.*/(1)
+    b/*<-local1*/ <- List/*->scala::package.List.*/(1)
     if b/*->local1*/ >/*->scala::Int#`>`(+3).*/ 1
-    c/*<-local2*//*->local2*/ = a/*->local0*/ +/*->scala::Int#`+`(+4).*/ b/*->local1*/
+    c/*<-local2*/ = a/*->local0*/ +/*->scala::Int#`+`(+4).*/ b/*->local1*/
   } yield (a/*->local0*/, b/*->local1*/, c/*->local2*/)
   for {
-    a/*<-local4*/ <- List/*->scala::package.List.*/(1)
-    b/*<-local5*/ <- List/*->scala::package.List.*/(a/*->local4*/)
+    a/*<-local3*/ <- List/*->scala::package.List.*/(1)
+    b/*<-local4*/ <- List/*->scala::package.List.*/(a/*->local3*/)
     if (
-      a/*->local4*/,
-      b/*->local5*/
+      a/*->local3*/,
+      b/*->local4*/
     ) ==/*->scala::Any#`==`().*/ (1, 2)
     (
-      c/*<-local7*/,
-      d/*<-local8*/
-    ) <- List/*->scala::package.List.*/((a/*->local4*/, b/*->local5*/))
+      c/*<-local6*/,
+      d/*<-local7*/
+    ) <- List/*->scala::package.List.*/((a/*->local3*/, b/*->local4*/))
     if (
-      a/*->local4*/,
-      b/*->local5*/,
-      c/*->local7*/,
-      d/*->local8*/
+      a/*->local3*/,
+      b/*->local4*/,
+      c/*->local6*/,
+      d/*->local7*/
     ) ==/*->scala::Any#`==`().*/ (1, 2, 3, 4)
-    e/*<-local9*//*->local9*/ = (
-      a/*->local4*/,
-      b/*->local5*/,
-      c/*->local7*/,
-      d/*->local8*/
+    e/*<-local8*//*->local8*/ = (
+      a/*->local3*/,
+      b/*->local4*/,
+      c/*->local6*/,
+      d/*->local7*/
     )
-    if e/*->local9*/ ==/*->scala::Any#`==`().*/ (1, 2, 3, 4)
-    f/*<-local10*/ <- List/*->scala::package.List.*/(e/*->local9*/)
+    if e/*->local8*/ ==/*->scala::Any#`==`().*/ (1, 2, 3, 4)
+    f/*<-local9*/ <- List/*->scala::package.List.*/(e/*->local8*/)
   } yield {
     (
-      a/*->local4*/,
-      b/*->local5*/,
-      c/*->local7*/,
-      d/*->local8*/,
-      e/*->local9*/,
-      f/*->local10*/
+      a/*->local3*/,
+      b/*->local4*/,
+      c/*->local6*/,
+      d/*->local7*/,
+      e/*->local8*/,
+      f/*->local9*/
     )
   }
 }

tests/semanticdb/metac.expect

@@ -1682,24 +1682,23 @@ Schema => SemanticDB v4
 Uri => ForComprehension.scala
 Text => empty
 Language => Scala
-Symbols => 13 entries
-Occurrences => 53 entries
-Synthetics => 23 entries
+Symbols => 12 entries
+Occurrences => 51 entries
+Synthetics => 22 entries
 
 Symbols:
 example/ForComprehension# => class ForComprehension extends Object { self: ForComprehension => +1 decls }
 example/ForComprehension#`<init>`(). => primary ctor <init> (): ForComprehension
 local0 => param a: Int
 local1 => param b: Int
 local2 => val local c: Int
-local3 => param x$1: Tuple2[Int, Int]
-local4 => param a: Int
-local5 => param b: Int
-local6 => param x$1: Tuple2[Int, Int]
-local7 => val local c: Int
-local8 => val local d: Int
-local9 => val local e: Tuple4[Int, Int, Int, Int]
-local10 => param f: Tuple4[Int, Int, Int, Int]
+local3 => param a: Int
+local4 => param b: Int
+local5 => param x$1: Tuple2[Int, Int]
+local6 => val local c: Int
+local7 => val local d: Int
+local8 => val local e: Tuple4[Int, Int, Int, Int]
+local9 => param f: Tuple4[Int, Int, Int, Int]
 
 Occurrences:
 [0:8..0:15): example <- example/
@@ -1708,60 +1707,55 @@ Occurrences:
 [4:4..4:5): a <- local0
 [4:9..4:13): List -> scala/package.List.
 [5:4..5:5): b <- local1
-[5:4..5:5): b -> local1
 [5:9..5:13): List -> scala/package.List.
 [6:7..6:8): b -> local1
 [6:9..6:10): > -> scala/Int#`>`(+3).
 [7:4..7:5): c <- local2
-[7:4..7:5): c -> local2
 [7:8..7:9): a -> local0
 [7:10..7:11): + -> scala/Int#`+`(+4).
 [7:12..7:13): b -> local1
 [8:11..8:12): a -> local0
 [8:14..8:15): b -> local1
 [8:17..8:18): c -> local2
-[10:4..10:5): a <- local4
+[10:4..10:5): a <- local3
 [10:9..10:13): List -> scala/package.List.
-[11:4..11:5): b <- local5
+[11:4..11:5): b <- local4
 [11:9..11:13): List -> scala/package.List.
-[11:14..11:15): a -> local4
-[13:6..13:7): a -> local4
-[14:6..14:7): b -> local5
+[11:14..11:15): a -> local3
+[13:6..13:7): a -> local3
+[14:6..14:7): b -> local4
 [15:6..15:8): == -> scala/Any#`==`().
-[17:6..17:7): c <- local7
-[18:6..18:7): d <- local8
+[17:6..17:7): c <- local6
+[18:6..18:7): d <- local7
 [19:9..19:13): List -> scala/package.List.
-[19:15..19:16): a -> local4
-[19:18..19:19): b -> local5
-[21:6..21:7): a -> local4
-[22:6..22:7): b -> local5
-[23:6..23:7): c -> local7
-[24:6..24:7): d -> local8
+[19:15..19:16): a -> local3
+[19:18..19:19): b -> local4
+[21:6..21:7): a -> local3
+[22:6..22:7): b -> local4
+[23:6..23:7): c -> local6
+[24:6..24:7): d -> local7
 [25:6..25:8): == -> scala/Any#`==`().
-[26:4..26:5): e <- local9
-[26:4..26:5): e -> local9
-[27:6..27:7): a -> local4
-[28:6..28:7): b -> local5
-[29:6..29:7): c -> local7
-[30:6..30:7): d -> local8
-[32:7..32:8): e -> local9
+[26:4..26:5): e <- local8
+[26:4..26:5): e -> local8
+[27:6..27:7): a -> local3
+[28:6..28:7): b -> local4
+[29:6..29:7): c -> local6
+[30:6..30:7): d -> local7
+[32:7..32:8): e -> local8
 [32:9..32:11): == -> scala/Any#`==`().
-[33:4..33:5): f <- local10
+[33:4..33:5): f <- local9
 [33:9..33:13): List -> scala/package.List.
-[33:14..33:15): e -> local9
-[36:6..36:7): a -> local4
-[37:6..37:7): b -> local5
-[38:6..38:7): c -> local7
-[39:6..39:7): d -> local8
-[40:6..40:7): e -> local9
-[41:6..41:7): f -> local10
+[33:14..33:15): e -> local8
+[36:6..36:7): a -> local3
+[37:6..37:7): b -> local4
+[38:6..38:7): c -> local6
+[39:6..39:7): d -> local7
+[40:6..40:7): e -> local8
+[41:6..41:7): f -> local9
 
 Synthetics:
 [4:9..4:13):List => *.apply[Int]
 [4:9..4:16):List(1) => List.apply[Int](*)
-[5:4..7:5):b <- List(1)
-    if b > 1
-    c => Tuple2.apply[Int, Int](*)
 [5:9..5:13):List => *.apply[Int]
 [5:9..5:16):List(1) => List.apply[Int](*)
 [8:10..8:19):(a, b, c) => Tuple3.apply[Int, Int, Int](*)