Re: Parsing perl 5 with perl 6 (was Re: Larry's Apocalypse 1)

[Jarkko Hietaniemi]

I don't get it.

The first and foremost duty of Perl 6 is to parse and execute Perl 6.
If it doesn't, it's not Perl 6.  I will call this the Prime Directive.

I think as the first approximation the implementation of Perl 6 should
get that "simple" task right.  If it doesn't, all our talk and work
has been for nothing and we have failed.

People seem to think that telling Perl 5 apart from Perl 6 is trivial.
In certain special cases, yes, such as the "module"/"class" versus
"package" distinction described by Larry, but in the general case that
is not not going to be easy, for example when the difference is
more syntatical.  Some Perl 5 things will by syntax errors in Perl 6,
and vice versa.

Truly detecting Perl5ness is hard: you will have to in essence
replicate the Perl 5 parsing, and we all know the amount of hair
in that code.  We really want to include such a hairball in our
new beautiful code?

Thinking about the 5->6 migration and coexistence is good and useful,
but since that doesn't advance the Prime Directive, thinking about it
*too* much now or fighting over the niggly details is somewhat wasted
effort.

-- 
$jhi++; # http://www.iki.fi/jhi/
        # There is this special biologist word we use for 'stable'.
        # It is 'dead'. -- Jack Cohen