From: Tom Cloyd <tomcloyd@...>
Date: 2009-04-23T02:34:41+09:00
Subject: Re: how to test for existence of a method

Jes�s Gabriel y Gal�n wrote:
> On Wed, Apr 22, 2009 at 12:43 PM, Robert Klemme
> <shortcutter@googlemail.com> wrote:
>   
>>> Chris Kottom wrote:
>>>       
>>>> Object#respond_to? doesn't do it for you?
>>>>         
>> This is unsafe:
>>
>> irb(main):001:0> o = Object.new
>> => #<Object:0x10171bb8>
>> irb(main):002:0> def o.method_missing(s,*a,&b) s == :foo ? "yes" : super end
>> => nil
>> irb(main):003:0> o.respond_to? :foo
>> => false
>> irb(main):004:0> o.respond_to? "foo"
>> => false
>> irb(main):005:0> o.foo
>> => "yes"
>> irb(main):006:0>
>>     
>
> Just a question: isn't it good practice to override respond_to? when
> you use method missing to handle things, so that it "tells the truth"?
> Or is it something people don't usually do?
>
> Jesus.
>
>
>   
How would you do this?

t.

-- 

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Tom Cloyd, MS MA, LMHC - Private practice Psychotherapist
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