phasers CHECK

Documentation for phasers CHECK assembled from the following types:

language documentation Phasers

From Phasers

(Phasers) phasers CHECK

Runs at compile time, As late as possible, only runs once.

Can have a return value that is provided even in later phases.

Code that is generated at run time can still fire off CHECK and INIT phasers, though of course those phasers can't do things that would require travel back in time. You need a wormhole for that.