From: Ken Collins <ken@...>
Date: 2006-10-04T21:34:06+09:00
Subject: Re: Using a Regexp to find a Hash Key?


I sure could...

The hash is going to be real small. It would at most only have 3 or 4  
keys. The one I want has a prefix of an arbitrary string with any  
amount of number after it. I need to know if this key is present so  
that I can run a conditional block of code. It would be a bonus to  
get some match data back on that last series of digits in the regexp.

I would like to use something like this:

def foobar
   if hash.has_key?(/^foo_\d+$/)
     ...
   end
end

Meanwhile my code looks like this and I was pretty sure there might  
be a more terse solution.

def foobar
   unless params.reject{ |k, v| k !~ /^foo_\d+$/ }.empty?
     ...
   end
end


On Oct 4, 2006, at 12:20 AM, Paul Lutus wrote:

> Ken Collins wrote:
>
>>
>
> This is possible, but it is rather cumbersome and slow, since the  
> regexp has
> to be applied to each hash key in turn until a match is found.
>
> Maybe you could provide more detail about the problem to be solved  
> instead
> of this notion about how to solve it. Even one word more.
>
> -- 
> Paul Lutus
> http://www.arachnoid.com
>