Re: Perl's parser and lexer will likely be in Perl (was Re: RFC 334 (v1) I'm {STILL} trying to understand this...)

[Jeremy Howard]

Leon Brocard wrote:
> Bradley M. Kuhn sent the following bits through the ether:
>
> > It should be noted that in Larry's speech on Friday, he said that he
wanted
> > to write the Lexer and Parser for Perl in some subset of Perl.  :)
>
> Is there a writeup somewhere for those who couldn't attend?
>
> Hmmm, I wonder what kind of subset would be necessary - surely the
> most useful constructs are also the most complicated...
>
We could learn quite a bit by looking through the code from
Parse::RecDescent, switch.pm, and friends. Damian's done a lot of parsing
(including parsing Perl) with Perl, so this would be a good place to start.

In terms of bootstrapping, however, we either need to:
 - Write the Perl subset in C (or some other portable language), or
 - Use Perl 5 as the 'Perl subset', and distribute that with Perl 6.

The 2nd of these options seems unlikely to be practical... Maybe however the
bootstrapper could be a subset of Perl 5 stolen fairly directly from the
existing code. Maybe this would then also become the Perl for small/embedded
devices.