[ruby-core:18278] Re: Am I right that this is wrong?

Hi --

On Thu, 14 Aug 2008, Gregory Brown wrote:

> On Wed, Aug 13, 2008 at 3:04 PM, David A. Black <[e-mail]> wrote:
>> Hi --
>>
>> On Thu, 14 Aug 2008, Yukihiro Matsumoto wrote:
>>
>>> Hi,
>>>
>>> In message "Re: [ruby-core:18263] Am I right that this is wrong?"
>>>   on Wed, 13 Aug 2008 22:33:18 +0900, "David A. Black"
>>> <[e-mail]> writes:
>>>
>>> |  *  call-seq:
>>> |  *     mod.instance_methods(include_super=true)   => array
>>> |  *
>>> |  *  Returns an array containing the names of public instance methods
>>> |  *  in the receiver. For a module, these are the public methods; for a
>>> |  *  class, they are the instance (not singleton) methods. With no
>>> |  *  argument, or with an argument that is <code>false</code>, the
>>> |  *  instance methods in <i>mod</i> are returned, otherwise the methods
>>> |  *  in <i>mod</i> and <i>mod</i>'s superclasses are returned.
>>> |
>>> |Since include_super defaults to true, I believe the "With no argument"
>>> |statement is wrong. These arbitrary boolean arguments are definitely
>>> |confusing, so I just wanted to make sure I'm right that it's wrong.
>>>
>>> The documentation is wrong, as you say.  If many prefer the documented
>>> behavior and want to change it, it is another story.
>>
>> There was a discussion about this at the Ruby Hoedown. As Jim Weirich
>> pointed out, the nice thing about doing it the other way around is
>> that you could do:
>>
>>  MyClass.instance_methods(:ancestors => true)
>>
>> or
>>
>>  MyClass.instance_methods(:with_ancestors)
>>
>> or whatever, whereas to make the argument false, you have to use false
>> or nil which is very cryptic.
>
> Are you suggesting keeping a boolean signature and then passing things
> like this in?
> I think that's a little nasty.
>
> I've done stuff like:
>
> some_method_with_boolean_args(do_something=true)
>
> But I would feel uncomfortable with
>
> some_method_with_boolean_args(:do_something)
>
> I'm totally aware that in practice, there is little difference between the two.
> However, I dislike the idea of a convention that creates a 'fake'
> signature, especially in the first case.
>
> MyClass.instance_methods(:ancestors => true)
>
> makes me think that I can do:
>
> MyClass.instance_methods(:ancestors => false), and without a change to
> the signature, that wouldn't be the case.

I would actually prefer there to be separate methods for all these
permutations (and I think Jim W. agrees). I just dislike the cryptic
"false" so much that I'd rather do almost anything else.


David

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