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Postings from May 2023
On 2023-05-02 21:33, Ovid wrote:
> Attributes could really use a rethink in a number of ways and I'm
> curious if anyone has put any thought into this?
>
> For example, attributes in signatures are a syntax error:
>
> sub foo ($bar :some_attr) { ... }
>
> It would also be nice if the attribute arguments could be dynamic
> instead of just strings. Here's an example, using the signatures from
> Type::Tiny. I have some client code which looks like this:
>
> use Custom::Sigs 'search_signature';
>
> signature_for function => search_signature();
>
> sub function {...}
>
> That particular signature is shared in several places, so it's
> maintained in only one place. At a minimum, I'd love to do this:
>
> use Custom::Sigs 'SEARCH';
>
> sub function :signature(SEARCH) {...}
>
> And replace SEARCH with the results of the sub call without nasty eval
> hacks. I'm actually working on some code to try to handle the latter
> case, but so far I've been using the Marpa parser to develop a BNF
> grammar to parse the Perl code in the attribute and install the
> signature. It's very painful.
>
The set of instances of <function> could be implemented as
a set of minimal instances called <_function>,
and a single "wrapper" implementation of <function> itself inside some role,
that handles all the interfacing,
and then hands over to the appropriate instance of <_function>?
-- Ruud
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