Finding methods of instance itself

[listrecv]

I use IRB to explore. Very often I type a.methods.sort, to see what an
object can do. The problem is, you're hit with 100 methods from Object
(or the superclass).

I've experimented with:
a.methods - a.class.superclass.methods
which works well for simple things

but it doesn't seem to handle cases when there are a lot of included
modules. Any ideas on how to see the methods defined in a.class only,
and not in any superclass or included module?

 

[transfire]

I use IRB to explore. Very often I type a.methods.sort, to see what an
object can do. The problem is, you're hit with 100 methods from Object
(or the superclass).

I've experimented with:
a.methods - a.class.superclass.methods
which works well for simple things

but it doesn't seem to handle cases when there are a lot of included
modules. Any ideas on how to see the methods defined in a.class only,
and not in any superclass or included module?

methods has a switch:

object.methods(false)

and

klass.instance_methods(false)

Also, keep in mind the differences between:

methods
public_methods
private_methods
protected_methods

instance_methods
public_instance_methods
private_instance_methods
protected_instance_methods

I've made a fool of myself more than once thinking the first combined
the later three -- it does not. methods is alias of public_methods and
likewise for the instance version.

T.

 

[listrecv]

methods has a switch:

object.methods(false)

and

klass.instance_methods(false)

Thanks!

 

[Pit Capitain]

Also, keep in mind the differences between:

methods
public_methods
private_methods
protected_methods

instance_methods
public_instance_methods
private_instance_methods
protected_instance_methods

I've made a fool of myself more than once thinking the first combined
the later three -- it does not.

Me too.

methods is alias of public_methods and
likewise for the instance version.

That's not quite correct. Kernel#methods and Module#instance_methods
return both public and protected methods:

class C
public; def pub; end
protected; def prot; end
private; def priv; end
end

p C.instance_methods(false) # => ["prot", "pub"]

Regards,
Pit

 

[Paul Battley]

I use IRB to explore. Very often I type a.methods.sort, to see what an
object can do. The problem is, you're hit with 100 methods from Object
(or the superclass).

I've experimented with:
a.methods - a.class.superclass.methods
which works well for simple things

but it doesn't seem to handle cases when there are a lot of included
modules. Any ideas on how to see the methods defined in a.class only,
and not in any superclass or included module?

This isn't exactly the answer to your question, but I've defined a
couple of methods in my .irbrc that I've found really useful. The
first is methods aliased to methods.sort (because that's always what I
want in irb, and the overhead doesn't matter there). The second is
distinct_methods, which is all the methods that aren't inherited from
Object:

class Object
alias_method :__methods__, :methods
def methods
return __methods__.sort
end
def distinct_methods
(__methods__ - Object.__methods__).sort
end
end

The latter generally produces a manageable list, so I haven't found
the need to exclude methods from included modules or superclasses.

Paul.