Re: Using sub routines or AUTOLOAD for XS constants

If you're getting the error message "can't locate exported subroutine $name via $class" from Sub::Exporter's default_generator(), the best option is to override can() in your package when you use AUTOLOAD(). That's a good practice anyway, though.

I haven't tested this code, but something like this should work:

sub can
{
    my ($class, $name) = @_;

    return if $name eq 'constant';
    my ($error, $val) = constant($name);

    return if $error;
    my $sub = sub () { $val };

    {
        no strict 'refs';
        *{ $class . '::' . $name } = $sub;
    }

    return $sub;
}
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Re^2: Using sub routines or AUTOLOAD for XS constants by ikegami (Patriarch) on Jan 01, 2010 at 22:23 UTC
Sub::Exporter uses `can`? That's a bug. `can` is for methods, and it makes no sense to export methods.	[reply] [d/l] [select]
Re^3: Using sub routines or AUTOLOAD for XS constants by chromatic (Archbishop) on Jan 02, 2010 at 10:25 UTC
`can` is for methods... I agree in principle, but what's the difference in practice between a method and a function, at least when you're groveling through a package's symbol table? There's likely a bug lurking in Sub::Exporter here as well, if it ever tries to export an inherited function.	[reply] [d/l]
Re^4: Using sub routines or AUTOLOAD for XS constants by ikegami (Patriarch) on Jan 02, 2010 at 19:55 UTC
It means there's a hole (false positives) in the error checking the author apparently desires, and it probably allows it to export inherited subs are a result.	[reply]
Re^2: Using sub routines or AUTOLOAD for XS constants by aflott (Beadle) on Jan 01, 2010 at 20:54 UTC
Yes that is exactly what I was looking for. Although I had to add `return \&{$class . '::' . $name} if (defined(&{$name}));` for having the non-constant subs reachable. Thanks for the nudge in the right direction.	[reply] [d/l]