On Mon, Apr 16, 2001 at 02:49:07PM -0500, Jarkko Hietaniemi wrote:
> 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.
Great, but don't loose sight of the fact that a key feature of "Perl 6",
as far as Larry's sketched it out, is the ability to dynamically alter
the parser in both dramatic and subtle ways.
Following your lead, I will call this the Prime Language Feature :)
> People seem to think that telling Perl 5 apart from Perl 6 is trivial.
My reading of Larry's comments is that it will be _made_ trivial at the
file scope level. If the file doesn't start with Perl 6 thingy then
it's Perl 5. Period.
> 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?
My reading of Larry's comments is that it won't be "in" our ``new
beautiful code''? [Umm, pride before a fall?]
That beautiful code will be beautifully _open_ to _external_ extensions.
And that is how I imagine that Perl 5 support should be implemented.
The parser is, ooops, the parsers are (plural) going to be in perl, remember.
> Thinking about the 5->6 migration and coexistence is good and useful,
> but since that doesn't advance the Prime Directive,
I disagree.
> thinking about it *too* much now or fighting over the niggly details
> is somewhat wasted effort.
Now this I agree with. It's quite staggering how much hot air has been
generated from Larry's first significant outline. Much of it missing,
or casually disregarding, key points of deep or subtle meaning.
I'm reminded of the long threads about bignum support that seemed to
be lost in the details of _a_ bignum implementation rather than
focusing on the design of a generic type extension mechanism that would
then enable multiple bignum implementations to coexist.
Tim.
