Cats Files

Cats v2.9.0 is a binary-compatible release in the 2.x series. It is published for Scala 2.12, 2.13, and 3.2+ with Scala.js 1.8+ and Scala Native 0.4.

What's Changed

Features

• Added updated to Traverse by @nikololiahim in https://github.com/typelevel/cats/pull/4248
• Added zipWithLongIndex, mapWithLongIndex and traverseWithLongIndexM by @nikololiahim in https://github.com/typelevel/cats/pull/4247
• Add collectFirst to the NonEmptyCollection interface by @DavidGregory084 in https://github.com/typelevel/cats/pull/4275
• Added discipline tests for the new Traverse laws by @nikololiahim in https://github.com/typelevel/cats/pull/4283
• Add traverseCollect to TraverseFilter typeclass by @emilhotkowski in https://github.com/typelevel/cats/pull/4277
• Add NonEmptyList#prependAll by @saeltz in https://github.com/typelevel/cats/pull/4267
• Add EitherT#biSemiflatTap which combines leftSemiflatTap and semiflatTap by @exp0nge in https://github.com/typelevel/cats/pull/4293
• Optimize Alternative (part 3): add prependK/appendK specializations for Cats NE wrappers by @satorg in https://github.com/typelevel/cats/pull/4055
• Added parFlatMapN by @TonioGela in https://github.com/typelevel/cats/pull/4243
• Added Align instances for Id and Kleisli by @atnoya in https://github.com/typelevel/cats/pull/4287
• Add ApplicativeError#voidError by @armanbilge in https://github.com/typelevel/cats/pull/4324

Optimizations

• Change the ordering of invocations in Defer#fix by @TimWSpence in https://github.com/typelevel/cats/pull/4252
• Optimise boilerplate generators, use instance constructors by @joroKr21 in https://github.com/typelevel/cats/pull/3871
• Avoid using NonFatal.unapply by @jhnsmth in https://github.com/typelevel/cats/pull/4282
• Use SAM syntax for typeclass instances where possible by @joroKr21 in https://github.com/typelevel/cats/pull/4279
• Singleton monoid instances by @TimWSpence in https://github.com/typelevel/cats/pull/4314
• Avoid allocations for Monoid instances where possible by @bplommer in https://github.com/typelevel/cats/pull/4309
• Make string building a bit more efficient for NonEmptySeq by @danicheg in https://github.com/typelevel/cats/pull/4326

Fixes

• Don't require Order for the value on Cogen for SortedMap and NonEmptyMap by @cquiroz in https://github.com/typelevel/cats/pull/4296
• Make cats.compat a package object for for2_13Use3 compatibility by @TonioGela in https://github.com/typelevel/cats/pull/4315
• Fix ambiguous contains_ syntax by @armanbilge in https://github.com/typelevel/cats/pull/4320

Deprecations

• Deprecate HashLaws#sameAsUniversalHash by @armanbilge in https://github.com/typelevel/cats/pull/4319

Documentation

• Remove LEGO from adopters list by @hejfelix in https://github.com/typelevel/cats/pull/4242
• Fix Free Monad example by @youta32449999 in https://github.com/typelevel/cats/pull/4253
• Mention asRight and asLeft for constructing Either values by @benhutchison in https://github.com/typelevel/cats/pull/4257
• Fix comment in Free Monad example by @youta32449999 in https://github.com/typelevel/cats/pull/4259
• Add proof of inconsistency for a Validated Monad by @TonioGela in https://github.com/typelevel/cats/pull/4255
• Mention tupled syntax, a Cats workhorse that deserves to be more well known by @benhutchison in https://github.com/typelevel/cats/pull/4269
• Add missing scala modifier to code block by @armanbilge in https://github.com/typelevel/cats/pull/4274
• Build docs on 2.13 by @armanbilge in https://github.com/typelevel/cats/pull/4238
• Fix list formatting in docs / site by @valencik in https://github.com/typelevel/cats/pull/4290
• Move the adopters' companies list to a separate file/page by @danicheg in https://github.com/typelevel/cats/pull/4291
• Keep the cats version up to date on the website by @danicheg in https://github.com/typelevel/cats/pull/4294
• Include laws in published API docs by @armanbilge in https://github.com/typelevel/cats/pull/4318
• Fix markdown syntax for link to Applicative in OptionT by @yoshinorin in https://github.com/typelevel/cats/pull/4321
• Add more DocTests for OptionT by @timo-schmid in https://github.com/typelevel/cats/pull/4311

Behind-the-scenes

• Ignore updates to cats-core by @armanbilge in https://github.com/typelevel/cats/pull/4241
• Bump base version to 2.9 by @armanbilge in https://github.com/typelevel/cats/pull/4239
• Refactored Chain and CollectiveMonoid benchmarks by @TonioGela in https://github.com/typelevel/cats/pull/4264
• Fix obvious and straightforward warnings by @satorg in https://github.com/typelevel/cats/pull/4323
• Add commits to .git-blame-ignore-revs by @armanbilge in https://github.com/typelevel/cats/pull/4334
• Add stack-safety test for ContT#map by @eigenvariable in https://github.com/typelevel/cats/pull/4335
• Add release notes config by @armanbilge in https://github.com/typelevel/cats/pull/4330

Updates

• Update sbt-scalajs, scalajs-compiler, ... to 1.10.1 by @typelevel-steward in https://github.com/typelevel/cats/pull/4254
• Update nscplugin, sbt-scala-native, ... to 0.4.7 by @typelevel-steward in https://github.com/typelevel/cats/pull/4289
• Update scalacheck to 1.17.0 by @typelevel-steward in https://github.com/typelevel/cats/pull/4297
• Update scala3-library, ... to 3.2.1 by @typelevel-steward in https://github.com/typelevel/cats/pull/4337

New Contributors

• @hejfelix made their first contribution in https://github.com/typelevel/cats/pull/4242
• @youta32449999 made their first contribution in https://github.com/typelevel/cats/pull/4253
• @nikololiahim made their first contribution in https://github.com/typelevel/cats/pull/4248
• @TonioGela made their first contribution in https://github.com/typelevel/cats/pull/4255
• @emilhotkowski made their first contribution in https://github.com/typelevel/cats/pull/4277
• @valencik made their first contribution in https://github.com/typelevel/cats/pull/4290
• @exp0nge made their first contribution in https://github.com/typelevel/cats/pull/4293
• @cquiroz made their first contribution in https://github.com/typelevel/cats/pull/4296
• @atnoya made their first contribution in https://github.com/typelevel/cats/pull/4287
• @yoshinorin made their first contribution in https://github.com/typelevel/cats/pull/4321
• @eigenvariable made their first contribution in https://github.com/typelevel/cats/pull/4335
• @timo-schmid made their first contribution in https://github.com/typelevel/cats/pull/4311

Full Changelog: https://github.com/typelevel/cats/compare/v2.8.0...v2.9.0