Re: idempotent (was Re: exif --remove not idempotent, and a Debian man page bug)
> rhkramer wrote:
>
> > An operation that produces the same results no matter how
> > many times it is performed.
>
> Yeah, obviously it is a term from math and in practical and
> applied engineering as is programming I thought of
> a definition (not really) like this
>
> - apply once, you get the change
>
> - apply twice, thrice, or n'ice, nothing happens since the
> change happened the first time and there is nothing to do
>
> Stefan and Tomás can tell I know...
>
> Anyway in math everyone understands it, and an example is the
> absolute value,
>
> abs(x) = ...
>
> abs(abs(x)) = ...
>
> abs..(abs(abs(x))) = ...
>
> Same!
>
> And that's pretty close to what I just said.
>
> The difference if any seems to be, in math focus is on the
> return value, so it is easy - is it the same or not?
>
> Im programming, focus is "can I apply it to make sure the job
> is done, and don't have to think - has it already been done? -
> because if so, no matter how many times, it won't ruin it,
> just nothing will happen over and over and whatever stuff it
> is applied on will be in the after-applied, desired form".
>
> That's right, right? Or am I wrong?
Sorry, but what's the practical point of all this discussion?
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