KCommand

KCommand is a revolutionary command library for kotlin FRC teams that expands off of WPILib's Command-based programming paradigm. With KCommand, teams can use an expressive domain-specific language to write commands that combine the benefits of WPILib's subclassed commands and command groups.

What does KCommand offer over the base java WPILib commands library?

BuildCommand DSL:

The buildCommand DSL essentially puts the JSON paradigm onto creating commands. The buildCommand DSL's syntax is designed to be easily readable while minimizing clutter and boilerplate code.

Here is a side-by-side comparison between a buildCommand and a regular command composition:

val commandGroup = ConditionalCommand(
     Commands.sequence(
         Commands.run({
             shooter.run()
             groundIntake.run()
         }, shooter, groundIntake).until{ noteObserver.state = State.NoteInShooter },
         Commands.run({
             shooter.run()
             groundIntake.run()
         }).withTimeout(0.4)
     ),
     Commands.none(),
     RobotBase::isReal
).finallyDo{ _ ->
     groundIntake.setIdle()
     shooter.setIdle()
}.withName("CommandGroup")

val buildCommand = buildCommand("BuildCommandName"){
     require(shooter, groundIntake)
     realRobotOnly {
         loopUntil({noteObserver.state = State.NoteInShooter}){
             shooter.run()
             groundIntake.run()
         }
         loopForDuration(0.4){
             shooter.run()
             groundIntake.run()
         }
     }
     onEnd {
         shooter.setIdle()
         groundIntake.setIdle()
     }
}

The buildCommand DSL also supports comprehensive logging with the log = true parameter.

Various command extensions:

Even if you do plan to stick with the regular WPILib commands library, KCommand offers more kotlin-friendly versions of various inline commands.

As of now, this consists of overloads of InstantCommand and RunCommand that uses external lambda syntax. For instance:

val runCommand = RunCommand(drivetrain) {
  drivetrain.drive()
}
// instead of
val oldRunCommand = RunCommand({
  drivetrain.drive()
}, drivetrain)

How do I install/use KCommand?

Our wiki has resources on installation, usage, and more!