Re: Implementing perl BEGIN blocks

[Autrijus Tang]

On Thu, Aug 18, 2005 at 04:51:58PM +0200, Leopold Toetsch wrote:
> There was some recent discussion [1] [2] on p6l about BEGIN blocks and 
> constant, which is executed at compile time too.
> 
> Parrot has since quite a time the @IMMEDIATE subroutine pragma, which 
> causes execution of subs during compilation.

You mean, during PIR compilation?

> As PMC constants are already represented as frozen images in PBC this 
> would work for nested data strucuters, objects, and their classes too.
> 
> Comments welcome,

I think it's interesting, but as BEGIN blocks may affect subsequent
parsing, as well as trigger compilation of other source files, I wonder
how to address this.  Hmm.

Also I wonder about scoping issues:

    {
        my $a = $a / 2;
        BEGIN { $a = 10 };
    }
    say $a; # this should to print 5

How is @IMMEDIATE going to handle this?

Thanks,
/Autrijus/

pgpcvuMn4K7uB.pgp
Description: PGP signature