Highlights of the release

• Add @scala.annotation.internal.preview annotation and -preview flag. #22317
• Make SIP-52 @publicInBinary a stable feature in 3.7 #22591
• Make SIP-58 - Named Tuples a stable feature in 3.7 #22753
• Make SIP-62 - Better Fors a preview feature in 3.7 #22776
• Implement SIP-61 @unroll annotation as experimental #21693
• Implement SIP-68 Reference-able Package Objects as experimental #22011
• Upgrade Scala 2 Standard Library to 2.13.16 #22386
• Upgrade Scala.js to 1.18.1. #22397
• Upgrade Scala CLI to 1.7.0 #22735
• Expression Compiler is now part of Scala 3 compiler #22597
• Quotes API: Added apply methods to import selectors #22457
• Quotes API: Implement experimental summonIgnoring method #22417
• Quotes API: Add class parameters, flags, and privateWithin and annotations to experimental newClass methods #21880
• Experimental: Capture Calculus - Inferring tracked modifier #21628
• Presentation Compiler: Show inferred type on holes in hover #21423
• JVM Backend: Fix #15736 blocking Scala 3 on Android #22632
• REPL: add flag to quit after evaluating init script #22636
• REPL: implement :jar (deprecate :require) #22343
• Linting: Improvements to -Wunused and -Wconf #20894
• Implicit parameters warn at call site without using keyword #22441
• Minimal support for dependent case classes #21698

Other changes and fixes

Annotations

• Lift arguments of explicitly constructed annotations #22553
• Fix copy of annotation on @main methods #22582
• @publicInBinary has now effect on secondary constructors #22630
• Fix mapping of annotations #22407

Backend: Scala.js

• Emit js.NewArray IR nodes when possible. #22446

Classpath

• Fix empty ClassPath attribute in one or more classpath jars causes crash #22462

Documentation

• Improve the usage of inclusive language #22360

Erasure

• Handle type aliases in contextFunctionResultTypeAfter #21517
• Align erasure of Array[Nothing] and Array[Null] with Scala 2 #22517

Desugering

• Under betterFors don't drop the trailing map if it would result in a different type (also drop _ => ()) #22619

Experimental: Capture Checking

• Canonicalize capture variable subtype comparisons #22299
• Permit Capture Refs for Uninitialized Type and Term Params in BiTypeMap #22451
• Fix maximal capability handling and expand aliases #22341

Experimental: Modularity

• Widen skolem types when adding parent refinements #22488

Experimental: Global Initialization Checker

• Refactor the abstract domain of global init checker to compile http4s #22179
• Fix global init checking crash when using a value defined in by-name closure #22625

Experimentals

• Expand value references to packages to their underlying package objects #22011

Implicits

• Restrict implicit args to using #22458

Linting

• Suppress spurious Suppression #22383
• CheckUnused checks span.exists before testing its parts #22504
• Don't warn retainedBody #22510
• Handle Typeable #22663
• Nowarn public implicit val class params #22664
• Exclude synthetic this.m, Any.m from import lookup #22695
• Warn unused member of anonymous class #22729
• Ignore params to default arg getters #22749
• Lazy val def member is pattern var #22750
• Restore resolving prefixes of implicit Ident #22751
• No warning for parameter of overriding method #22757
• Dealias before checking for member in lint #22708
• Warn on bad extensions of aliases #22362
• Warn universal extensions on opaque types #22502
• Discourage default arg for extension receiver #22492
• Rename on import is never wildcard #22712
• Collect nowarn symbols instead of skipping them #22766

Match Types

• Handle NoType in TypeComparer.disjointnessBoundary #21520

Named Tuples

• Special case NamedTuple.From for arguments derived from Tuple #22449
• Generate mirrors for named tuples #22469

Opaque Types

• Fix stack overflow errors when generating opaque type proxies #22479
• Fix inline proxy generation for opaque types referencing other opaque types #22381
• Fix opaque types leaking rhs when inlined and found in type params (and a related stale symbol issue) #22655

Overloading

• Make overload pruning based on result types less aggressive #21744

Parser

• Fix annotations being not expected in the middle of an array type by java parser #22391
• No outdent at eof #22435
• Allow observing an indent after conditional #22611
• Correctly detect colon lambda eol indent for optional brace of argument #22477

Pattern Matching

• Avoid crash in uninhab check in Space #22601
• Account for named tuples in space subtraction #22658
• Check exhaustivity of any case class #22604

Presentation Compiler

• Add enum type param support in sourceSymbol #18603
• Map name position to desugared version of named context bound #22374
• Hover and go to definition for named tuples #22202
• Completions: do not complete package #20532
• Print parens for single method argument only if a direct tuple type #21510
• Improvement: use heuristic to figure out nameSpan if pointDelta too big #22484
• Fix inferredTypeEdits for symbols #22485
• Fix: Only fallback to the definition of a synthetic valdef if it is zero extent #22551
• Better LSP completions inside of backticks #22555
• Don't search for members in pc info when irrelevant #22674
• Backport from Metals #22426
• Backport from Metals #22491
• Backport from Metals #22665

Runner

• Upgrade Scala CLI to 1.7.0 highlights
  • Switch to scalameta/scalafmt images of scalafmt 3.9.1+ #3502
  • Support the --test command line option for run subcommand #3519
  • Support the --test command line option for package subcommand #3519
  • Detect objects with main class in scripts #3479
  • Support for Scala.js 1.18.2 #3454
  • Support for Scala Native 0.5.7 #3527
  • Add support for running a main method from the test scope #3502

Quotes

• Add a check for correct Array shape in quotes.reflect.ClassOfConstant #22033
• Fix issue with static this references erroring in quoted code #22618
• Fix #21721: make case TypeBlock(,) not match non-type Block #21722
• Make Ref.apply() return trees usable in the largest scope possible #22240
• Make sure Block does not incorrectly match a TypeBlock #22716
• Do not approximate prefixes when using memberType in reflect API #22448
• Bring back pattern match exhaustivity checking for macros #22622

REPL

• REPL: JLine 3.29.0 (was 3.27.1) #22679
• Repl: emit warning for the :sh command #22694
• Add warning for :kind command #22572

Reporting

• Filter help renders box border #22434
• Register nowarn when inlining #22682
• Rule out exports of member of the current class #22545

Scaladoc

• Render @deprecated correctly even when named arguments weren't used #21925
• Remove DRI from Scaladoc warnings #22330

SemanticDB

• Don't add () to semanticdb symbol for java variables #22573
• Fix compiler crash when using betasty with missing java classfiles #22599

Transform

• Check only stable qual for import prefix #22633
• Treat static vals as enclosures in lambdalift #22452
• Record calls to constructors in lambdaLift #22487
• Only check logicalOwners for methods, and not for classes, when looking for proxies #22356
• Add error-checking when fetching rhs of trees from TASTy #22565

Typer

• Root of Java select must be class or rooted package #21800
• Check if a prefix is valid before selecting from a type #22368
• Preserve hard unions in widenSingletons #22369
• Constructor proxy is restricted if class is protected #22563
• Constructor companion gets privateWithin #22627
• Revert lambda cleanup #22697
• Avoid infinite recursion when looking for suggestions #22361
• Fix cyclic check, regardless of definition order #22342
• Avoid inf recursion in provablyDisjointClasses #22489

Value Classes

• Allow private members when computing the denotation of a NamedType #22549

Other changes

• Remove locale dependent FileSystemException check #21633

Known issues

Critical issues discovered after Scala 3.7.0-RC1 release - these would be fixed in subsequent RC release before 3.7.0:

• Running tests with munit and Scala.js breaks for Scala 3.7 #22794

Contributors

Thank you to all the contributors who made this release possible 🎉

According to git shortlog -sn --no-merges 3.6.4..3.7.0-RC1 these are:

    59  Martin Odersky
    43  Som Snytt
    33  Adrien Piquerez
    32  Hamza Remmal
    21  Wojciech Mazur
    19  aherlihy
    19  kasiaMarek
    15  Jan Chyb
    13  Dale Wijnand
    11  Kacper Korban
    10  EnzeXing
     7  Guillaume Martres
     7  Matt Bovel
     7  Oliver Bračevac
     7  noti0na1
     6  Sébastien Doeraene
     5  HarrisL2
     5  Jamie Thompson
     5  dependabot[bot]
     4  Joel Wilsson
     4  Seth Tisue
     3  Piotr Chabelski
     3  Roman Janusz
     3  anna herlihy
     2  David Hua
     1  Alec Theriault
     1  Daisy Li
     1  Daniel Thoma
     1  Dmitrii Naumenko
     1  Felix Herrmann
     1  He-Pin(kerr)
     1  João Ferreira
     1  Jędrzej Rochala
     1  Katarzyna Marek
     1  Kenji Yoshida
     1  Niklas Fiekas
     1  Rocco Mathijn Andela
     1  Vadim Chelyshov
     1  Yichen Xu
     1  adpi2
     1  fan-tom
     1  philwalk
     1  rochala