executor

• isOpen method to indicate if the Executor is still accepting tasks.

• Updated lints.

• Fix tasks with non-nullable return types when an error is thrown. (#4 by davidmartos96)

• Migrated to null safety (by swdyh)

• Updated code to Dart 2.7.0 and latest lints.
• Fix: task completion updates the running count immediately.

• Removed new keyword, and updated to follow package:pedantic rules.
• Executor.join will register Future.catchError on task futures, preventing uncaught exceptions from blocking further execution.
• Simplified execution and trigger mechanism.

• Using package:stack_trace to chain async stacktraces when task fails.

• Improved design on loop and scheduling, preserving caller stacktrace with full details.

• Removed Timers to schedule tasks, using a simple loop instead.
• Better distribution for rate-limited executions.

• Supporting Dart 2 only.

• Dart2 compatibility with package:dart2_constant.

Breaking changes

• Removed deprecated member limit.
• Renamed ExecutorTask -> AsyncTask, return value to FutureOr.
• Renamed Rate.limit -> Rate.maximum.

New features

• Added Executor.onChange. Clients can use this to monitor the current scheduledCount and queue more tasks to ensure Executor is running on full capacity.

Housekeeping

• Added example.
• Added a few tests.

• Expose internal stats: runningCount, waitingCount, scheduledCount.
• Enable sync-points with join(), which allows to track the completion of the currently running (and optionally the waiting) tasks.

• Fix missing heartbeat check on Executor.close(), without it the Future might not have completed.