From: dblack@...
Date: 2007-08-08T23:50:29+09:00
Subject: Re: case statement

Hi --

On Wed, 8 Aug 2007, Jano Svitok wrote:

> On 8/8/07, Shai Rosenfeld <shaiguitar@gmail.com> wrote:
>> Alex Young wrote:
>>> Shai Rosenfeld wrote:
>>>> end
>>>>
>>>> ((i.e, whatever value is included in the array))
>>>> ...how do i do this?
>>>
>>> Does the Array#include? method do what you need?  Perhaps a more
>>> fleshed-out example might help?
>>
>> Array#include is EXACTLY what i need, but syntaxtetically (if u get the
>> drift) i'm not sure how to do it:
>>
>> case [3, 45, 6, 'abc'].inlcude?
>> when 1: 'no good'
>> when 3: 'good!'
>> when 'lolo': 'no good'
>> end
>>
>> (the above doesn't work. it's gives a 'not enough arguments' error. how
>> do i do it correctly?)
>
> You could possibly do something like the following, but it's pretty dangerous:
>
> class Object
> 	 alias_method :old_case_equal, :===
>
> 	 def ===(other)
> 		case other
> 		when Array:
> 			other.include? self
> 		else
> 			old_case_equal(other)
> 		end
> 	 end
> end

Let's go back to the "pretty dangerous" thing :-)  I think this is
beyond the acceptable danger threshold; you're actually making it so
that Array#=== won't work any more, which could really make things
blow up.


David

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