[Pdx-pm] fun with import()

chromatic chromatic at wgz.org
Sun Aug 6 13:45:00 PDT 2006

On Sunday 06 August 2006 11:04, Eric Wilhelm wrote:

> If any module anywhere does "use UNIVERSAL;" or "require UNIVERSAL",
> everyone automatically is using Exporter::import() unless they
> explicitly declared their own import sub.  Bug?

Yep, and a nasty one as it allows you to say:

	use UNIVERSAL 'isa';

... and:

	use UNIVERSAL 'can';

... and pretend as if isa() and can() are functions.  (They're not.  Is anyone 
getting tired of hearing me say this yet?  Tell your friends.)

The comment in UNIVERSAL.pm reads:

	# The use of Exporter below is a historical
	# accident that can't be fixed without breaking code.  Note that we
	# *don't* set @ISA here, don't want all classes/objects inheriting from
	# Exporter.  It's bad enough that all classes have a import() method
	# whenever UNIVERSAL.pm is loaded.

I did fix the documentation in bleadperl to suggest therapy instead of 
importing isa() and can(); I'm not sure if it went into maintperl at some 

-- c

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