typelevel/cats-effect v1.0.0-RC3

on GitHub

This is the third release candidate before 1.0. The only planned changes before the final release are documentation and an upgrade to cats-1.3.0 when it is released.

List of Changes

New data types:

• Clock (doc) — #289
• ContextShift (doc) — #289

Major behavioral / breaking changes:

• #278: New encoding of Resource
• #282: Change laws for Bracket and Concurrent to support auto-cancelable and streaming types
• #290: Changes to concurrency and cancellation:
  • Concurrent#cancelable is no longer a primitive.
  • Replace IO[Unit] with F[Unit] as the cancellation token, aliased to CancelToken[F]
  • IO#unsafeRunCancelable now returns a CancelToken[IO] to support backpressure
• #298: Introduce SyncIO, which becomes return type in Effect#runAsync and ConcurrentEffect#runCancelable
• #296: Sync extends cats.Defer
• #289, #307: Separation of concerns in Timer:
  • Timer#shift moved to new ContextShift
  • Timer#clockMonotonic and Timer#clockRealtime moved onto Timer#clock
  • Timer.deriveIO is removed.
  • Added derived Timer instances for various monad transformers over F[_].
• #309: Remove Effect#runSyncStep
• #311: Make IO auto-cancelable after async boundaries and remove IO#onCancelRaiseError

Added features:

• #266: Update implicitNotFound error message in Timer
• #269: Add Resource.fromAutoCloseable
• #249: Add Applicative[Fiber[F, ?]] instance given Concurrent[F]
• #305: Backpressure on IO cancellation tokens to support sequenced finalizers
• #289: Improved support for blocking APIs with ContextShift#evalOn

Docs:

• #263: Replace Task's mentions with IO from MVar docs
• #264, #283: Cleanup to documentation for Ref
• #292, #300: Typo fixes
• #300: Document stack safety as another use case for IO.shift
• #303: Remove redundant Parallel[IO, IO] instance from Deferred docs
• #302: Document SyncIO
• #304: List related projects
• #287: New guide to concurrency basics

Bug fixes and chores:

• #274: Test against Oracle JDK 10
• #273: Build with sbt-1.1.6
• #275: Build with scala-2.12.6, scalatest-3.0.5
• #293: Remove deprecated procedure syntax
• #294: Build for scala-2.13.0-M4 and with cats-1.2.0

Getting Involved

You can always help with:

1. Feedback by joining us on Gitter
2. Re-tweet the [release announcement]
3. Give us a star on GitHub 🙂

Special Thanks

This release was made possible by: @Avasil, @bthuillier, @adamw, @sullis, @aoiroaoino, @alexandru, @kubokoz, @vaslabs, @LukaJCB, @xuwei-k, @mpilquist, @dscleaver, @ericlurla, @gvolpe, @pchlupacek, @rossabaker, @ChristopherDavenport and several other reviewers and commenters.

Thanks to all those involved!