sabre-io/event

• #50: Fixed Promise\all to resolve immediately for empty arrays (@MadHed)
• #48, #49: Performance optimisations for EmitterTrait and WildcardEmitterTrait (@lunixyacht).

• #45: Fixed Emitter class to use the correct interface. (@felixfbecker).

• #42: The coroutine function now supports return in the passed generator
  function. This allows you to more generally return a value. This is a BC
  break as this is a feature that was only made possible with PHP 7, and
  before the coroutine function would only ever return the last thing that
  was yielded. If you depended on that feature, replace your last yield with
  a return.

• sabre/event now requires PHP 7. If you need PHP 5.5 support, just keep
  using 3.0.0.
• PHP 7 type hints are now used everywhere. We're also using strict_types.
• Support for a new WildcardEmitter which allows you to listen for events
  using the * wildcard.
• Removed deprecated functions Promise::error and Promise::all. Instead,
  use Promise::otherwise and Promise\all().
• EventEmitter, EventEmitterTrait and EventEmitterInterface are now just
  called Emitter, EmitterTrait, and EmitterInterface.
• When rejecting Promises, it's now required to use an Exception or
  Throwable. This makes the typical case simpler and reduces special cases.

• Now requires PHP 5.5!
• Promise::all() is moved to Promise\all().
• Aside from the Promise\all() function, there's now also Promise\race().
• Promise\reject() and Promise\resolve() have also been added.
• Now 100% compatible with the Ecmascript 6 Promise.

Also contains all the changes from the previous alpha:

• #26: Added an event loop implementation. Also knows as the Reactor Pattern.
• Renamed Promise::error to Promise::otherwise to be consistent with
  ReactPHP and Guzzle. The error method is kept for BC but will be removed
  in a future version.
• #27: Support for Promise-based coroutines via the Sabre\Event\coroutine
  function.
• BC Break: Promises now use the EventLoop to run "then"-events in a separate
  execution context. In practise that means you need to run the event loop to
  wait for any then/otherwise callbacks to trigger.
• Promises now have a wait() method. Allowing you to make a promise
  synchronous and simply wait for a result (or exception) to happen.

• This release has no functional changes. It's just been brought up to date
  with the latest coding standards.

• Fixed: $priority was ignored in EventEmitter::once method.
• Fixed: Breaking the event chain was not possible in EventEmitter::once.

• Added: When calling emit, it's now possible to specify a callback that will be
  triggered after each method handled. This is dubbed the 'continueCallback' and
  can be used to implement strategy patterns.
• Added: Promise object!
• Changed: EventEmitter::listeners now returns just the callbacks for an event,
  and no longer returns the list by reference. The list is now automatically
  sorted by priority.
• Update: Speed improvements.
• Updated: It's now possible to remove all listeners for every event.
• Changed: Now uses psr-4 autoloading.