Hi --

On Tue, 23 Oct 2007, Randy Kramer wrote:

> On Tuesday 23 October 2007 07:44 am, Robert Klemme wrote:
>> 2007/10/23, Randy Kramer <rhkramer / gmail.com>:
>>> On Tuesday 23 October 2007 12:46 am, Konrad Meyer wrote:
>>>> Push and pop have been around as instructions since the days of asm. The
>>>> common "visualisation" is to imagine a dinner-plate-stack-holder at a
>>> buffet.
>>>> You push plates down into the spring-loaded stack to add more. When you
> want
>>>> to remove a plate, you pop it out of the top of the stack. That's
> probably
>>>> not the best description of the idea, but you can always google for
>>> push/pop.
>>>
>>> I always liked that visualization.  The problem for me (and I'm not the
> OP) is
>>> that in Ruby you have to lift all the plates off, put the new plate on the
>>> bottom, and then put all the plates back.  (Likewise when you want to
> "pop"
>>> that plate.)  ;-)  (Because Ruby uses push and pop on the end of the array
>>> instead of the beginning.)
>>
>> I'm not sure what exactly you mean.  #push and #pop just work as one
>> would expect from a LIFO.
>
> Well, it was partly an attempt at humor, and partly the result of some strange
> coding I did recently in a program to convert files in what I call askRhk03
> format to askRhk04 format.
>
> In doing that, I had the need (or it seemed convenient) to both push and pop
> things on to the array, but then also access all the items in the array in
> order.  (I.e., using something like array.each { }
>
> But, the first time I attempted it, without noticing that a push occurred on
> the end of the array instead of the beginning, I got the wrong results.  (No
> big deal, I just used array.reverse first.)

Have a look at #shift and #unshift.


David

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