Finding methods of instance itself

Ruby
1

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?

2

[email protected] wrote:

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.

3

[email protected] wrote:

methods has a switch:

object.methods(false)

and

klass.instance_methods(false)

Thanks!

4

[email protected] schrieb:

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

5

On 19/07/06, [email protected] [email protected] wrote:

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.