--- Moritz Lenz <[EMAIL PROTECTED]> wrote:
> Ovid wrote:
> > Anyone have any idea why Google is not indexing the official Perl 6
> > documentation at perlcabal.org/syn? I checked the robots.txt and
> it
> > looks fine:
> >
> > http://www.perlcabal.org/robots.txt
> >
> > But the search box on http://www.perlcabal.org/syn/ returns
> nothing.
>
> The whole domain seems to be missing from the index, not only the
> synopsis.
>
> If nobody else has any idea, I could get a webmaster account and try
> to
> find out what's wrong.
>
> > Specifically, I was looking for the documentation on how subsets
> work
> > as it looks like we can get declarative style constraint
> programming
> > for free:
> >
> > subset Crosshair of Point where { $_.inside_of($target_zone) };
> >
> > Is that valid syntax?
>
> Yes. See http://perlcabal.org/syn/S02.html#Polymorphic_types for
> similar
> examples.
Well, looking at the examples that you and Jonathan listed, I see I
should refine my question. For example:
subset Crosshair of Point where {
$_.inside_of($target_area)
||
$target_area.has_moved
?? $_.move_inside($target_area)
:: $target_area.move_outside($_)
};
In other words, I think we could get proper constraint programming if a
subset can mutate its variable. Otherwise, all assignment would need
to be wrapped inside of an eval and the code would be more bug-prone.
Will said mutating work? If it does, all logic handling constraints
can be encapsulated in one spot. On the other hand, this could lead to
mysterious action at a distance. The losses are significant, but the
wins seem absolutely fascinating.
Cheers,
Ovid
--
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