[Cel Skeggs]

At long last! CCRE prerelease 3.0.0-pre1 is out! It's only been 3-4 months.

This is not quite yet the final 3.0.0 release, but it's close, it has a huge list of improvements, and it works!

Full changelog:

Prerelease of CCRE with API 3.0.0-pre1.

Highlights:

* Structure: Removed support for cRIO.
* Structure: Started using Java 8 features everywhere.
* Dataflow: Removed pollability as a dimension of complexity.
* Dataflow: Moved *Mixing methods to instead be default methods on interfaces.
* FRC and roboRIO: Renamed Igneous to FRC.
* Documentation: Added a new Scribble-based documentation system.
* Deployment: Added DeploymentEngine system to manage deployment to robots, which is many times faster than WPILib's deployment tool.

Documentation changes:

* Added a new Scribble-based documentation system.
* Removed examples from last year's FIRSTFare presentation and added this year's examples.
* Continuous integration via Travis CI is now in use, which covers unit testing and checking of certain code maintenance targets, such as keeping license headers up-to-date. This should help future maintainers.
* Javadocumented just about everything important.

Dataflow changes:

* Removed InputPolls. Inputs only now.
* Added DerivedInputs, which replace some functionality of InputPolls.
* Pollable I/O is replaced by interfaces which take polling events and return updating I/O.
* Moved *Mixing methods to instead be default methods on interfaces.
* Added UpdatingInput as a superinterface of the *Input classes.
* send is no longer a fundamental method, but an implementation on top of the new onUpdate.
* Removed `unsend` and replaced it with unsubscription EventOutputs returned by the `send` family of methods.
* Renamed Statuses to Cells and extracted IOs as superinterfaces that merge Inputs and Outputs.
* Converted PIDControl into PIDController and inverted control to make more sense.
* Support for taking derivatives of float channels.
* Added miscellaneous new remixing methods and constant fields.
* Renamed EventStatus.clearListeners to __UNSAFE_clearListeners.

Error handling changes:

* Let setupRobot() and autonomousMain() throw Throwables.
* Added safeSet/safeEvent for top-level handling of errors.
* Removed EventOutputRecoverable and restructured error handling to ensure consistent propagation.

FRC and roboRIO changes:

* Renamed Igneous to FRC.
* Shorted names of everything in FRC.
* Removed the WPILibJ-wrapping style of FRC/Igneous implementation. Direct is the only implementation now.
* Added support for FPGA Counters on the roboRIO.
* Removed WPILib Eclipse plugins as a dependency.
* Added sensorPeriodic as the default polling interval in FRC.
* Renamed IgneousLauncher to FRCImplementation.
* Removed the driver station screen I/O methods.
* Added simpleControl of CAN to FRC and ExtendedMotor.

Deployment and build changes:

* Added DeploymentEngine system to manage deployment to robots, which is many times faster than WPILib's deployment tool.
* Removed dependency on Git in build process; versions are now specified in a source file.

Control interface changes:

* All Joysticks have POV hats now.
* Converted POV hat accesses to angle checks rather than angle and press accessors.
* Added AbstractJoystick to assist conversion of pollable interfaces into updating interfaces.
* Added default ControlBinding.
* Renamed IJoystick to Joystick.

Structural changes:

* Removed support for cRIO.
* Started using Java 8 features everywhere.
* Renamed all of the projects to have shorter and more accurate names.
* Changed expected project structure; added script to autoupgrade projects to v3 structure.
* Removed CCRE Collections.

Testing changes:

* Added FakeTime, for faking time in tests.
* Converted test infrastructure to JUnit.
* Unit tested huge sections of the CCRE that weren't before.

Miscellaneous changes:

* Added an abstraction for Time, for use in time-influenced testing.
* Renamed StorageProvider to Storage.
* Made StorageSegment its own implementation: now final instead of abstract.
* Slimmed down ExpirationTimer.
* Slimmed down StateMachine slightly.
* Added support abstractions for the dataflow event dispatch infrastructure.
* Added utility to rewrite CRLFs to LFs.
* Added miscellaneous support abstractions.
* Rearranged a few packages.
* Renamed just about everything to make meanings clearer.

Networking changes:

* Deabstracted the networking system and integrated traffic metrics.
* Added versioning to the Cluck protocol, which is backwards-compatible with v2.x.x Cluck, but only until the first protocol version increment.
* Added ability to subscribe to IOs.
* Deprecated Cluck UNSUB messages; they are replaced with NACKs.
* Cells are no longer RConfable.
* Removed default PoultryInspector link naming.
* Removed openDataInputStream and openDataOutputStream from ClientSocket.
* Removed minimum logging levels from network logging.
* Removed old Cluck searching methods.

UI changes:

* Resized Emulator components so that they require less screen space.
* Added window title to PoultryInspector.

Removals:

* Removed support for Phidget.
* Removed BooleanFilter.
* Removed StringHolder.
* Removed IgneousCore.
* Removed BootLogger.
* Removed ccre.launcher.Launcher dispatcher.
* Removed RLoad client and server.
* Removed Tokenizer.
* Removed the CCRE_Examples project.
* Removed MultipleSourceBooleanController.
* Removed Utils.currentTimeSeconds.
* Removed cRIO workarounds.
* Removed alternate storage implementations.
* Removed miscellaneous premature optimizations.
* Removed all sorts of deprecated and outdated methods.
* Removed deprecated EventOutput and updateWhen code in InstinctModule.
* Removed ApolloGemini2014 and InfernoDante examples.
* Removed vestigal kinect support, as it was only easily supported with the cRIO.
* Removed other vestigal and deprecated utility methods.

Implementation changes:

* Moved useCustomCompressor into FRC.

Bugfixes:

* Fixed incorrect disabling of digital outputs in emulator.
* Improved all sorts of bounds and argument checks throughout the CCRE.
* Fixed lots of edge cases.
* Fixed encoding incompatibilities and standardized on UTF-8.
* Fixed incorrect error propagation when broadcasting.
* Added missing top-level error handling.
* Fixed some miscellaneous race conditions.
* Fixed incorrect naming of mecanum drive code.

The length of that list should hopefully justify how long this release took to get out the door. Keep in mind that the thing with adding more unit tests took a lot longer than the single changelog line might imply.

Highlights:

• Being a major-number release, we were allowed to break backwards compatibility for the first time since v2.0.0! This was part of the inspiration for many of the changes made.
• We removed support for the cRIO. Getting Java 8 to work on the cRIO would have been more of a challenge than we wanted to take on.
• Thanks to that, the CCRE now takes advantage of a significant chunk of Java 8's featureset! Default interfaces are the biggest advantage, because they allow us to have both a) easily implemented channels AND b) remixing methods on the channels themselves.
• We realized that the InputPoll versus Input dichotomy was not helpful in real programs, and only made things more complicated. So, we got rid of it! Everything's an Input now. To replace the previous ease of defining new InputPolls, there are now DerivedInputs that are almost as easy (for defining InputPolls) and much much easier (for defining Inputs.)
• We renamed a very large number of things in this release, because the old names weren't very helpful. For example: the Igneous subsystem is now called the FRC subsystem.
• We added an entire new style of documentation. Check it out here! This uses Racket's Scribble system, which is good for guidebooks like this. This documentation is not yet complete, but should be a good place to start with the new version.
• We wrote the DeploymentEngine to simplify the deployment of code to FRC robots, and it just so happened that it also sped up everything by a significant margin!
• On a related note, we got rid of our dependency on WPILib's Eclipse plugins, so installation is smoother than ever.

Looking towards the future, we have some more changes planned for the final 3.0.0 release, which should be coming in a few weeks. We do have the opportunity to make more backwards-incompatible changes for that release, but we've made most of them by now, so don't worry too much about that.

We also plan to do things like Eclipse plugins so that you don't have to download the CCRE source to use it!

One quick note on upgrading to CCRE 3: we have a tool that will offer to upgrade your v2.x.x projects for you. Simply import your old project into your new CCRE 3 workspace, and press Build All. You should be asked if you want to upgrade your project to CCRE 3: make sure your old code is backed up, and then press Yes and type in your team number. This won't do everything for you, but will do the easy things like replacing InputPolls with Inputs, replacing Igneous with FRC, and handling most of the other major renamings. You will have to manually move your Mixing invocations to the new system, however.