From: Harry Kakueki <list.push@...>
Date: 2007-05-14T23:02:29+09:00
Subject: Re: Hash#shift

On 5/14/07, Robert Klemme <shortcutter@googlemail.com> wrote:
> I never had use for this myself but it might be useful in cases where
> you want to iterate through a (possibly temporary) Hash and make sure
> that elements that you have processed are removed.  Like
>
>  >> h={:foo=>1, :bar=>2, :baz=>3}
> => {:baz=>3, :foo=>1, :bar=>2}
>  >> until h.empty?
>  >>   k, v = h.shift
>  >>   puts "processing: #{k} - #{v}"
>  >> end
> processing: baz - 3
> processing: foo - 1
> processing: bar - 2
> => nil
>  >> h
> => {}
>
> If you now leave the loop early (for whatever reasons, "return" or
> raise) you only leave elements that still have to be processed in the Hash.
>
> Kind regards
>
>         robert
>
>

OK.
You would be shifting in a somewhat random order but you would be able
to keep track of what had not yet been shifted.

Thanks for that example.

Harry

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