From: Jim Moy <web@...>
Date: 2003-12-16T10:29:39+09:00
Subject: Re: [Nuby] Object ID Lookup?

>>   a = { "a" => 1, "b" => 2 }
>>   b = { "c" => 4, "d" => 3 }
>>   arr = [a, b]
>>   ids = arr.collect {|h| h.id}
>>   lookup = {}
>>   arr.each { |h| lookup[h.id] = h }
>>   cmp = ids.collect {|id| lookup[id]}
>>   ids == cmp => true
>>
>> In my instance, I've got a reference set of hashes that I'm
>> pointing to from multiple arrays.  Those arrays are manipulated
>> depending on sorting and other factors.
>>
>> I don't want to get Hash#== involved so I'm using the Hash
>> object id's.  After processing is completed, I'd like to get
>> back from the IDs to the object references.  The lookup is
>> working, but I was wondering if there was a better method.
>
> Eric Hodel (drbrain@segment7.net) wrote:
>
> Not seeing the internals of your code, will Object#equal? (identical
> object ids) be able to replace #==?

Yes, the code similar to the above example works as-is with the
hash ids, as I wanted to avoid Hash#== and all the comparisons it
will perform.  Judging by the replies so far, I think I'll keep
the lookup hash.

Jim