3.3.0-RC2

This release is nearly identical to 3.3.0-RC1. The only difference is that 3.3.0-RC1 generated output with incorrect TASTy version.

The following changelog is identical to the changelog of 3.3.0-RC1.

Highlights of the release

• Stabilize new lazy vals #16614
• Experimental Macro annotations #16392 #16454 #16534
• Fix stability check for inline parameters #15511
• Make fewerBraces a standard feature #16297
• Add new front-end phase for unused entities and add support for unused imports #16157
• Implement -Wvalue-discard warning #15975
• Introduce boundary/break control abstraction. #16612

Other changes and fixes

Annotations

• Support use-site meta-annotations #16445

Desugaring

• Reuse typed prefix for applyDynamic and applyDynamicNamed #16552
• Fix object selftype match error #16441

Erasure

• Dealias before checking for outer references in types #16525
• Fix generic signature for type params bounded by primitive #16442
• Avoid EmptyScope.cloneScope crashing, eg on missing references #16314

GADTs

• Inline GADT state restoring in TypeComparer #16564
• Add extension/conversion to GADT selection healing #16638

Incremental compilation

• Unpickle arguments of parent constructors in Templates lazily #16688

Initialization

• Fix #16438: Supply dummy args for erroneous parent call in init check #16448

Inline

• Dealias in ConstantValue, for inline if cond #16652
• Set Span for top level annotations generated in PostTyper #16378
• Interpolate any type vars from comparing against SelectionProto #16348
• Handle binding of beta reduced inlined lambdas #16377
• Do not add dummy RHS to abstract inline methods #16510
• Warn on inline given aliases with functions as RHS #16499
• Support inline overrides in value classes #16523

Java interop

• Represent Java annotations as interfaces so they can be extended, and disallow various misuses of them #16260

Opaque Types

• Delay opaque alias checking until PostTyper #16644

Overloading

• Handle context function arguments in overloading resolution #16511

Parser

• Improve support for Unicode supplementary characters in identifiers and string interpolation (as in Scala 2) #16278
• Require indent after colon at EOL #16466
• Help givens return refined types #16293

Pattern Matching

• Tweak AvoidMap's derivedSelect #16563
• Space: Use RHS of & when refining subtypes #16573
• Freeze constraints in a condition check of maximiseType #16526
• Restrict syntax of typed patterns #16150
• Test case to show that #16252 works with transparent #16262
• Support inline unapplySeq and with leading given parameters #16358
• Handle sealed prefixes in exh checking #16621
• Detect irrefutable quoted patterns #16674

Pickling

• Allow case classes with up to 254 parameters #16501
• Correctly unpickle Scala 2 private case classes in traits #16519

Polyfunctions

• Fix #9996: Crash with function accepting polymorphic function type with singleton result #16327

Quotes

• Remove contents of inline methods #16345
• Fix errors in explicit type annotations in inline match cases #16257
• Handle macro annotation suspends and crashes #16509
• Fix macro annotations spliceOwner #16513

REPL

• REPL: Fix crash when printing instances of value classes #16393
• Attempt to fix completion crash #16267
• Fix REPL shadowing bug #16389
• Open up for extensibility #16276
• Don't crash if completions throw #16687

Reflection

• Fix reflect typeMembers to return all members #15033
• Deprecate reflect Flags.Static #16568

Reporting

• Suppress follow-on errors for erroneous import qualifiers #16658
• Fix order in which errors are reported for assignment to val #16660
• Fix class name in error message #16635
• Make refined type printing more source compatible #16303
• Add error hint on local inline def used in quotes #16572
• Fix Text wrapping #16277
• Fix -Wunused:import registering constructor <init> instead of its owner (also fix false positive for enum) #16661
• Fix #16675 : -Wunused false positive on case class generated method, due to flags used to distinguish case accessors. #16683
• Fix #16680 by registering Ident not containing a symbol #16689
• Fix #16682: CheckUnused missed some used symbols #16690
• Fix the non-miniphase tree traverser #16684

Scala-JS

• Fix #14289: Accept Ident refs to js.native in native member rhs. #16185

Standard Library

• Add CanEqual instance for Map #15886
• Refine Tuple.Append return type #16140

TASTy format

• Make it a fatal error if erasure cannot resolve a type #16373

Tooling

• Add -Yimports compiler flag #16218
• Allow BooleanSettings to be set with a colon #16425

Transform

• Avoid stackoverflow in ExplicitOuter #16381
• Make lazy vals run on non-fallback graal image - remove dynamic reflection #16346
• Patch to avoid crash in #16351 #16354
• Don't treat package object's <init> methods as package members #16667
• Space: Refine isSubspace property & an example #16574

Typer

• Drop requirement that self types are closed #16648
• Disallow constructor params from appearing in parent types for soundness #16664
• Don't search implicit arguments in singleton type prefix #16490
• Don't rely on isProvisional to determine whether atoms computed #16489
• Support signature polymorphic methods (MethodHandle and VarHandle) #16225
• Prefer parameterless alternatives during ambiguous overload resolution #16315
• Fix calculation to drop transparent classes #16344
• Test case for issue 16311 #16317
• Skip caching provisional OrType atoms #16295
• Avoid cyclic references due to experimental check when inlining #16195
• Track type variable dependencies to guide instantiation decisions #16042
• Two fixes to constraint solving #16353
• Fix regression in cyclic constraint handling #16514
• Sharpen range approximation for applied types with capture set ranges #16261
• Cut the Gordian Knot: Don't widen unions to transparent #15642
• Fix widening logic to keep instantiation within bounds #16417
• Skip ambiguous reference error when symbols are aliases #16401
• Avoid incorrect simplifications when updating bounds in the constraint #16410
• Take @targetName into account when resolving extension methods #16487
• Improve ClassTag handling to avoid invalid ClassTag generation and inference failure #16492
• Fix extracting the elemType of a union of arrays #16569
• Make sure annotations are typed in expression contexts #16699
• Throw a type error when using hk-types in unions or intersections #16712

Contributors

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

According to git shortlog -sn --no-merges 3.2.2..3.3.0-RC1 these are:

   225 Martin Odersky
    73 Dale Wijnand
    58 Szymon Rodziewicz
    54 Nicolas Stucki
    48 Kamil Szewczyk
    48 Paul Coral
    30 Paweł Marks
    28 Florian3k
    28 Yichen Xu
    14 Guillaume Martres
     8 Fengyun Liu
     8 Michał Pałka
     7 Chris Birchall
     7 rochala
     6 Kacper Korban
     6 Sébastien Doeraene
     6 jdudrak
     5 Seth Tisue
     5 Som Snytt
     5 nizhikov
     4 Filip Zybała
     4 Jan Chyb
     4 Michael Pollmeier
     4 Natsu Kagami
     3 Jamie Thompson
     2 Alex
     2 Anatolii Kmetiuk
     2 Dmitrii Naumenko
     2 Lukas Rytz
     2 adampauls
     2 yoshinorin
     1 Alexander Slesarenko
     1 Chris Kipp
     1 Guillaume Raffin
     1 Jakub Kozłowski
     1 Jan-Pieter van den Heuvel
     1 Julien Richard-Foy
     1 Kenji Yoshida
     1 Philippus
     1 Szymon R
     1 Tim Spence
     1 s.bazarsadaev