develooper Front page | perl.perl6.users | Postings from June 2018

Re: mixin syntax: does vs but

Thread Previous | Thread Next
JJ Merelo
June 12, 2018 19:16
Re: mixin syntax: does vs but
Message ID:
This is what the documentation says:
You can override it, but we'll pay no attention anyway, basically. So you
can't achieve it otherwise, I guess.

El mar., 12 jun. 2018 a las 21:14, JJ Merelo (<>)

> El mar., 12 jun. 2018 a las 21:11, Brandon Allbery (<>)
> escribió:
>> I should clarify this, but I'm not recalling full details at the moment
>> which is why I didn't originally.
>> Perl uses a metaobject protocol (MOP, which you'll see in various places
>> in the docs). The "macro" to access the metaobject is the .HOW
>> pseudo-method. If you do this for a normal class or object of that class,
>> you get Perl6::Metamodel::ClassHOW back. This is what the .^method syntax
>> is accessing; it's short for (thing).HOW.method((thing), ...). The
>> metaclass doesn't magically know its children, so the object has to be used
>> once to get at its metaclass and a second time to tell the metaclass what
>> it is to introspect.
>> I'm not seeing documentation for what .WHAT actually does; it (correctly)
>> notes that it's implemented specially within the compiler (hence "macro")
>> but not how you achieve it otherwise. Then again, .HOW has the same issue;
>> there's a bit of a bootstrapping issue with getting at the metamodel, you
>> need to have it first. Which is why it's wired into the compiler and gets
>> those uppercase pseudo-method names.
> All the metamodel is not exactly part of the language; it's part of the
> compiler. So it's in the gray NOT-SPECCED zone regarding documentation of
> "Perl 6" the language, as oposed to "Perl 6, the implementation by Rakudo".
> But it's a gray zone and sometimes you fall short of documenting things
> like WHAT. I'll see what we can in that area.
> JJ


Thread Previous | Thread Next Perl Programming lists via nntp and http.
Comments to Ask Bjørn Hansen at | Group listing | About