From: Vance A Heron <heron@...>
Date: 2005-10-04T13:47:16+09:00
Subject: Re: Odd hash behaviour

Kev,
Seems to work for me ...
$ irb
irb(main):001:0> @min_pks = Hash.new()
=> {}
irb(main):002:0> key = 'MID'
=> "MID"
irb(main):003:0> @min_pks[key] = 1 unless @min_pks.has_key?(key)
=> 1
irb(main):004:0> @min_pks[key] = 2 unless @min_pks.has_key?(key)
=> nil
irb(main):005:0> p @min_pks
{"MID"=>1}
=> nil

Could you give the rest of your code and possibly some sample
data?

Vance
On Tue, 2005-10-04 at 12:56 +0900, Kev Jackson wrote:
> Hi all,
> 
> I'm still munging data and I'm struggling with Ruby's hash
> 
> For example, I want to store a value with an associated key (sounds like 
> a hash or associated array), but I don't want duplicates (more like a 
> set, in Java I'd use a HashSet to get this behaviour).
> 
> @min_pks = Hash.new()
> ....
> # store value for key unless we already have it
> @min_pks[min_key] = no unless @min_pks.has_key?(min_key)
> 
> Regardless of how I structure the above, the Hash always stores every 
> value, it's as if the Hash always returns a false to the query has_key?, 
> so it always stores a new value
> 
> The key I'm using is a 3 letter abbreviation like 'MID', 'MCY' etc, and 
> in the incoming data they are duplicated
> 
> I've tried googling, I've tried ri etc, and there doesn't seem to be a 
> Set class with Ruby (I'd rather not write my own), at least according to 
> the docs.  I'm also aware that the problem is between the keyboard and 
> the chair, it's not Ruby's falut, I'm doing something dim.
> 
> Anyone help me out?
> 
> Kev
>