Signature attributes

Hi all,

Currently, the following is a syntax error:

    sub foo ($bar :myAttr) {...}

This has proven to be a blocker for some projects which use attributes on
declarations. For example, the Oshun project (
https://github.com/Perl-Oshun/oshun) to create dynamic runtime data checks
had to jump through a lot of hoops to make this work:

    sub customer :returns(OBJ[My::Customer] | UNDEF)  ( $nth :of(UINT) ) {
        ...
    }

If we had attributes for signatures, it wouldn't be an unholy mess of PPR
and Filter::Simple.

How difficult would it be to allow subroutine arguments to accept
attributes?

Alternatively, perldoc -f my allows my TYPE VARLIST, but sub foo (INT $bar)
generates:

    A signature parameter must start with '$', '@' or '%' at -e line 1

But TYPE isn't currently used much, so I'm guessing that's probably of less
value, though we've considered that syntax for the Oshun data checks.

Best,
Ovid
-- 
Curtis "Ovid" Poe
--
CTO, All Around the World
World-class software development and consulting
https://allaroundtheworld.fr/

• Signature attributes by Ovid
• Re: Signature attributes by Paul "LeoNerd" Evans
• Re: Signature attributes by Ovid
• Re: Signature attributes by Paul "LeoNerd" Evans
• Re: Signature attributes by Branislav Zahradník
• Re: Signature attributes by Ovid