Start from a main routine

When executed with the standard setting, Raku code always runs the mainline code automatically, followed by the MAIN function if you have one. However, it's possible to start up with an alternate setting that might want to create its own event loop or MAIN. In such cases you can always capture control at various phases with blocks that we call "phasers":

BEGIN {...} # as soon as parsed
CHECK {...} # end of compile time
INIT {...}  # beginning of run time
END {...}   # end of run time