From: "NARUSE, Yui" <naruse@...>
Date: 2011-12-05T05:02:29+09:00
Subject: [ruby-core:41482] Re: [ruby-trunk - Bug #5694][Open] Proc#arity doesn't take optional arguments into account.

(2011/12/04 12:41), NARUSE, Yui wrote:
> (2011/12/03 4:20), Yehuda Katz wrote:
>> Yeah��� it would be nice to be able to do:
>>
>>   if proc.arity_range.include?(2)
>>   if method.arity_range.include?(2)
> 
> Is it really required way?
> 
> For example you want to know whether you can obj.meth(a, b) or not,
> it should be something like obj.callable?(:meth, a, b), shouldn't it?

After some consideration, I'm wondering why following code is not used.
There is already a method or proc object in usual use case?

begin
  obj.__send__(callback, attributes)
rescue ArgumentError
  obj.__send__(callback)
end

-- 
NARUSE, Yui  <naruse@airemix.jp>