From: Joel VanderWerf <vjoel@...>
Date: 2008-07-07T03:36:00+09:00
Subject: Re: implementing a simple and efficient index system

Janus Bor wrote:
> I could also save all processed id's as keys of a hash, however I don't
> have any use for a value:
> 
> sequences = {}
> some kind of loop magic
>  if sequences[id]
>   process file
>   sequences[id] = true
>  end
> end
> 
> Would this method be more efficient? Is there a more elegant way? Also,
> can Ruby handle arrays/hashes of this size?

It's not so bad to use true as a hash value. But if it bothers you, 
there is the Set class, which is really a hash underneath, but the 
interface is set-membership rather than associative lookup:

require 'set'

s = Set.new

s << 123
s << 456

p s.include?(456) # ==> true
p s.include?(789) # ==> false

-- 
       vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407