Markus Laire wrote in perl.perl6.compiler :
>> my $use_debug_mode = BEGIN { %*ENV{DEBUGME} ?? 1 :: 0 };
>
> According to S04 you'd use INIT block for that. INIT is run at run time,
> ASAP. But BEGIN is run at compile time, ASAP.
Fair enough, makes sense. As long as BEGIN and CHECK blocks are run when
you evaluate code at run-time (which is not the case in perl 5 for CHECK
blocks currently)
> My example code:
> use v6;
> my $compile_begin_time = BEGIN { time() }
> my $compile_end_time = CHECK { time() }
> my $run_begin_time = INIT { time() }
> my %compile_time_environment = BEGIN { %*ENV }
> my %run_time_environment = INIT { %*ENV }
>
>
> (this list from http://dev.perl.org/perl6/synopsis/S04.html )
>
> BEGIN {...}* at compile time, ASAP
> CHECK {...}* at compile time, ALAP
> INIT {...}* at run time, ASAP
> END {...} at run time, ALAP
> FIRST {...}* at first block entry time
> ENTER {...}* at every block entry time
> LEAVE {...} at every block exit time
> KEEP {...} at every successful block exit
> UNDO {...} at every unsuccessful block exit
> NEXT {...} at loop continuation time
> LAST {...} at loop termination time
> PRE {...} assert precondition at every block entry
> POST {...} assert postcondition at every block exit
> CATCH {...} catch exceptions
> CONTROL {...} catch control exceptions
