[Chicago-talk] Object interogation

Steven Lembark lembark at wrkhors.com
Thu Oct 27 10:24:48 PDT 2005

-- Jay Strauss <me at heyjay.com>

> Randal L. Schwartz wrote:
>>>>>>> "Jay" == Jay Strauss <me at heyjay.com> writes:
>> Jay> Can you do the same with Perl?  I know you can ->can, but that
>> requires  Jay> prior knowledge of method names.  I can't think of how
>> you'd get object  Jay> attributes.
>> Yes.  You can look at the subroutines defined in the package of the
>> class.  However, you will not be able to tell which of those are
>> "really" methods and which are merely private subroutines.
>> sub UNIVERSAL::methods_of_class {
>>   my $this = shift;
>>   my $class = ref $this || $this;
>>   no strict 'refs';
>>   grep exists &$_, keys %{ $class . "::" };
>> }
> thanks Randal.  I was thinking there may be a more core built-in 
> facility than having to do it manually for each class.

The entire symbol table is fully exposed: there is 
nothing more "built in" than that.

Why would you want a list of all the methods supported
by an object (vs. asking whether the object supports a
given method using $obj->can( $method ))?

As for "private" subs, they can easily be privatized
via anon sub's (or a hash of them) and taken out of 
the symbol table if you are going to use this kind of 
interrogation on a regular basis.

Steven Lembark                                       85-09 90th Street
Workhorse Computing                                Woodhaven, NY 11421
lembark at wrkhors.com                                     1 888 359 3508

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