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Re: Getter performance

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On 11-10-21 10:57 PM, Daniel Pitts wrote:
> On 10/21/11 2:27 PM, Roedy Green wrote:
>> I think you should know without benchmarking each individual case
>> which Map or Collection would be best for a given task.

> I nearly agree.
> 
> An experienced programmer should know which Map or Collection would work
> sufficiently well for a given task.  "Best", by some definitions, would
> almost always be a custom class (perhaps not even implementing Map or
> Collection).  The thing is that best may be much better than needed.

Roedy may have meant "best" in this sense. It's a word with lots of
definitions, one of which is "most suitable". For a software
developer/engineer I'd think that "most suitable" would always be the
reigning definition of "best"; another definition (like the one you
posit as a possibility, leading perhaps to a custom class) might be more
of a computer science thing.

Roedy's right, though, with his overall comments, although I wouldn't
blame anything on The Donald [1]. For starters, way too many people -
having never read anything by Knuth except various quotes, have only
ever seen "premature optimization is the root of all evil" in isolation.
They've never read the important sentences surrounding that one, that
supply essential context.

I've seen it myself, that folks seize on this one sentence and disparage
reasonable design-time efforts to think about performance. And I've
heard often enough from other developers who should know better that we
should "write it first and we'll profile it later if it's too slow". Or
a memory hog. These folks forget that Knuth talked about _premature_
optimization: there's a lot of design and implementation-time
optimization that ain't.

c2.com on their page about "UniformlySlowCode"
(http://c2.com/cgi/wiki?UniformlySlowCode) discusses a situation that
can happen a lot if you don't practice experience-seasoned non-premature
optimization. I've seen this happen more than once, that an app is
sluggish and a memory beast, and yet when you analyze it you find that
you have to fix, well, everything.

AHS

1. Man, how can Trump be The Donald? It's just not right. :-) I've set
matters straight here.

-- 
I tend to watch a little TV... Court TV, once in a while. Some of the
cases I get interested in.
-- O. J. Simpson

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Getter performance Aéris <aeris@imirhil.fr> - 2011-10-15 23:03 +0200
  Re: Getter performance Arne Vajhøj <arne@vajhoej.dk> - 2011-10-15 17:36 -0400
    Re: Getter performance Arne Vajhøj <arne@vajhoej.dk> - 2011-10-15 17:42 -0400
      Re: Getter performance BGB <cr88192@hotmail.com> - 2011-10-15 15:00 -0700
        Re: Getter performance markspace <-@.> - 2011-10-15 15:20 -0700
          Re: Getter performance David Lamb <dalamb@cs.queensu.ca> - 2011-10-20 12:45 -0400
            Re: Getter performance Roedy Green <see_website@mindprod.com.invalid> - 2011-10-21 14:27 -0700
              Re: Getter performance Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-10-21 18:57 -0700
                Re: Getter performance Patricia Shanahan <pats@acm.org> - 2011-10-22 07:27 +0100
                Re: Getter performance Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-10-22 09:57 -0300
              Re: Getter performance Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-21 22:12 -0400
    Re: Getter performance Aéris <aeris@imirhil.fr> - 2011-10-15 23:59 +0200
      Re: Getter performance Arne Vajhøj <arne@vajhoej.dk> - 2011-10-15 19:44 -0400
        Re: Getter performance Aéris <aeris@imirhil.fr> - 2011-10-16 13:14 +0200
          Re: Getter performance Lars Enderin <lars.enderin@telia.com> - 2011-10-16 16:28 +0200
  Re: Getter performance Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-16 09:47 -0400
  Re: Getter performance Jaap Droogers <JaapDroogers@unusable.meel.homelinux.net> - 2011-10-16 22:12 +0200
    Re: Getter performance BGB <cr88192@hotmail.com> - 2011-10-16 13:58 -0700
    Re: Getter performance David Lamb <dalamb@cs.queensu.ca> - 2011-10-20 12:51 -0400
      Re: Getter performance Paul Cager <paul.cager@googlemail.com> - 2011-10-21 08:49 -0700
  Re: Getter performance Roedy Green <see_website@mindprod.com.invalid> - 2011-10-21 08:02 -0700
  Re: Getter performance Wanja Gayk <brixomatic@yahoo.com> - 2011-10-22 21:11 +0200

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