Command Groups

Command Groups have been much improved from the WPILib version. In Kotlin, Command Groups can be used like so:

val AutonomousAction = DriveForwards() and LiftArm() then OpenClaw()

AutonomousAction.start()

This AutonomousAction Command Group will run the DriveForwards command in parallel with the LiftArm command, then run OpenClaw after the previous two have completed.

Command Groups differ in a minor but important way from WPILib Command Groups. In WPILib, the addParallel command will start a command that runs in parallel with future commands. This isn't the expected result when writing Command Groups the Sertain way. In Sertain, parallel (or commands on either side of the and operator) commands will be run with the ones that come before it, and ensure that those complete before continuing past the next then statement. This can be thought about as converting the last parallel command in the sequence to a sequential command.