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Postings from November 2003
On Thu, Nov 06, 2003 at 07:32:45PM +0000, Graham Barr wrote:
> On Nov 6, 2003, at 2:00, Michael G Schwern wrote:
>
> >On Wed, Nov 05, 2003 at 09:05:52PM +0000, Graham Barr wrote:
> >>On Nov 4, 2003, at 23:13, Michael G Schwern wrote:
> >>>So, basically, you pick up an AUTOLOAD by inheriting from any module
> >>>that
> >>>uses XS. Feeling paranoid yet? :) Should we change can() to ignore
> >>>methods inherited from DynaLoader now?
> >>
> >>Thats been a known issue for a long time. The only reason you need to
> >>inherit from DynaLoader is that bootstrap may call the dl_load_flags
> >>method.
> >
> >Are you sure you mean dl_load_flags? It appears that the autoloaded
> >methods are:
>
> What has autoloaded subs got todo with inheritance ?
Sorry, I misparsed the above as "the only reason DynaLoader needs to inherit
from AutoLoader". AutoLoader on the brane.
> >>The annoying thing is that because you do have AUTOLOAD there then you
> >>get different warnings.
> >
> >I've been pondering changing the AutoLoader error message so it looks
> >a bit more like a normal method/function lookup failure. Possibly
> >placing the normal error in front of the extended AutoLoader
> >information.
> >This way at least checks like
> >$@ =~ /^Can't locate object method "$meth" via package "$class"/ will
> >still work.
>
> But AutoLoader::AUTOLOAD has no way to be sure if what is being
> attempted to be loaded was called as a method or a sub
Yeah, there's the rub. I wonder if it could take an educated guess somehow.
Check if the first argument is an object. Of course, then class methods
won't work. *ponder*.
Pragmaticly, I've rarely seen anyone check for.
$@ =~ /^Undefined subroutine &${pack}::$func called/
Having AutoLoader spit out the normal method lookup failure message,
regardless of whether it was a function or method call, is at least less
wrong than its current behavior. Doesn't really make me happy though.
Or we could do a fix for DynaLoader::AUTOLOAD similar to UNIVERSAL::import.
Limit its scope. Since the autoloaded things in DynaLoader are functions...
sub AUTOLOAD {
my($class, $meth) = $DynaLoader::AUTOLOAD =~ /^(.*)::([^:]+)$/;
croak qq{Can't locate object method "$meth" via package "$class"}
unless $class eq 'DynaLoader';
$AutoLoader::AUTOLOAD = $DynaLoader::AUTOLOAD;
goto &AutoLoader::AUTOLOAD;
}
This still leaves us with the wrong message should someone say:
package Foo;
require DynaLoader;
@ISA = qw(DynaLoader);
Foo::bar();
but its less wrong than "Can't locate auto/Foo/bar.al". With "Use of
inherited AUTOLOAD for non-method Foo::bar() is deprecated" warning
that goes along with it I think its less confusing.
--
Michael G Schwern schwern@pobox.com http://www.pobox.com/~schwern/
11. Every old idea will be proposed again with a different name and
a different presentation, regardless of whether it works.
-- RFC 1925
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