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Re: Help with Deck of cards assignment and getting it to deal...

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In article <Jd6dnaYWEdDi7WnOnZ2dnUVZ8jidnZ2d@bt.com>, Chris Uppal 
(chris.uppal@metagnostic.REMOVE-THIS.org) says...

> > You think that because Card is Comparable<> then people would mess up
> > the core game logic of comparing hands?
> 
> What I'd expect to see is people attempting to use the Comparable<> interface 
> regardless of the game rules.  And then patching their logic with ad-hoc 
> special cases when they realised that the pre-defined Comparable<> didn't do 
> exactly what the rules require.
> 
> Better not to set traps for the unwary.

Better not use Comparable at all. Put a Comparator implementation in sme 
public final field and use that instead, always.

While overriding hashCode and equals is often beneficial and correct, I 
find that implementing Comparable is often a mistake.

I've hat it numerous times that I ran into problems because some people 
implemented Comparable for some special purpose (like "sorting by 
name"), but did not implement equals and hashCode accordingly, because 
that would have messed up the rest (like equals was "equality by ID" or 
"all fields equal" and that must not be changed). What you end up with 
is objects that are equal according to "compareTo", but not equal 
according to "equals" and "hashCode".

And correcting that mistake later is a pain in the butt:
Try to find all arrays, lists, sets and other usages, where this class 
of objects might end up, search where these may be sorted or comparedto 
use a Comparator object instead.

Sure, you might run your test suite and set a breakpoint in the 
comparable implementation, but that will only take you so far as your 
test suite goes and let's be real: most programs have a rather lousy 
unit test coverage.

To put it with Glenn Danzig's words: "Do you want to cross that line? 
Cause it's a long way back from hell, and you don't want to go with me."

Kind regards,
Wanja

-- 
..Alesi's problem was that the back of the car was jumping up and down 
dangerously - and I can assure you from having been teammate to 
Jean Alesi and knowing what kind of cars that he can pull up with, 
when Jean Alesi says that a car is dangerous - it is. [Jonathan Palmer]

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Help with Deck of cards assignment and getting it to deal... Scott Dunning <scottwd01@gmail.com> - 2014-08-01 18:16 -0700
  Re: Help with Deck of cards assignment and getting it to deal... Roedy Green <see_website@mindprod.com.invalid> - 2014-08-02 01:42 -0700
    Re: Help with Deck of cards assignment and getting it to deal... Martin Gregorie <martin@address-in-sig.invalid> - 2014-08-02 10:19 +0000
      Re: Help with Deck of cards assignment and getting it to deal... Roedy Green <see_website@mindprod.com.invalid> - 2014-08-03 15:54 -0700
        Re: Help with Deck of cards assignment and getting it to deal... Martin Gregorie <martin@address-in-sig.invalid> - 2014-08-04 13:00 +0000
          Re: Help with Deck of cards assignment and getting it to deal... Arne Vajhøj <arne@vajhoej.dk> - 2014-08-19 17:48 -0400
            Re: Help with Deck of cards assignment and getting it to deal... "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-08-20 10:48 +0100
              Re: Help with Deck of cards assignment and getting it to deal... Arne Vajhøj <arne@vajhoej.dk> - 2014-09-07 21:42 -0400
              Re: Help with Deck of cards assignment and getting it to deal... Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-09-07 22:04 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Arne Vajhøj <arne@vajhoej.dk> - 2014-09-07 22:08 -0400
  Re: Help with Deck of cards assignment and getting it to deal... Mike Amling <mamling@chaff.us> - 2014-08-03 07:38 -0500
  Re: Help with Deck of cards assignment and getting it to deal... Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-08-03 10:23 -0400
    Re: Help with Deck of cards assignment and getting it to deal... lipska the kat <lipskathekat@example.com> - 2014-08-03 18:52 +0100
      Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 14:16 -0400
        Re: Help with Deck of cards assignment and getting it to deal... lipska the kat <lipskathekat@example.com> - 2014-08-03 19:21 +0100
          Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 14:38 -0400
            Re: Help with Deck of cards assignment and getting it to deal... lipska the kat <lipskathekat@example.com> - 2014-08-03 19:41 +0100
    Re: Help with Deck of cards assignment and getting it to deal... Mike Amling <mamling@chaff.us> - 2014-08-03 16:05 -0500
  Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 11:08 -0400
    Re: Help with Deck of cards assignment and getting it to deal... Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-08-03 11:41 -0400
      Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 13:25 -0400
        Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 13:36 -0400
          Re: Help with Deck of cards assignment and getting it to deal... David Postill <david.postill@gmail.com> - 2014-08-04 09:00 +0200
        Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 13:47 -0400
          Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 13:52 -0400
            Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 14:10 -0400
        Re: Help with Deck of cards assignment and getting it to deal... Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-08-03 15:00 -0400
          Re: Help with Deck of cards assignment and getting it to deal... Arne Vajhøj <arne@vajhoej.dk> - 2014-08-03 15:26 -0400
            Re: Help with Deck of cards assignment and getting it to deal... lipska the kat <lipskathekat@example.com> - 2014-08-03 20:34 +0100
            Re: Help with Deck of cards assignment and getting it to deal... Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-08-03 16:49 -0400
              Re: Help with Deck of cards assignment and getting it to deal... Arne Vajhøj <arne@vajhoej.dk> - 2014-08-03 17:01 -0400
                Re: Help with Deck of cards assignment and getting it to deal... "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-08-04 20:32 +0100
                Re: Help with Deck of cards assignment and getting it to deal... Arne Vajhøj <arne@vajhoej.dk> - 2014-08-19 17:45 -0400
                Re: Help with Deck of cards assignment and getting it to deal... "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-08-20 10:50 +0100
                Re: Help with Deck of cards assignment and getting it to deal... Brixomatic <brixomatic@yahoo.com> - 2014-08-31 10:17 +0200
                Re: Help with Deck of cards assignment and getting it to deal... "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-09-04 15:14 +0100
                Re: Help with Deck of cards assignment and getting it to deal... Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-09-04 10:55 -0400
                Re: Help with Deck of cards assignment and getting it to deal... "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-09-04 16:12 +0100
                [OT] Re: Help with Deck of cards assignment and getting it to deal... Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-09-04 15:05 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Gene Wirchenko <genew@telus.net> - 2014-09-05 10:03 -0700
                Re: Help with Deck of cards assignment and getting it to deal... Arne Vajhøj <arne@vajhoej.dk> - 2014-09-07 21:45 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-09-07 22:13 -0400
              Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 17:19 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-08-04 08:14 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-04 20:03 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-04 20:29 -0400
          Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 15:45 -0400
            Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 16:01 -0400
              Re: Help with Deck of cards assignment and getting it to deal... Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-08-03 17:05 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 17:37 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 18:19 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 18:34 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Eric Sosman <esosman@comcast-dot-net.invalid> - 2014-08-03 20:37 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 20:40 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 20:49 -0400
                Re: Help with Deck of cards assignment and getting it to deal... Jeff Higgins <jeff@invalid.invalid> - 2014-08-03 18:09 -0400
  Re: Help with Deck of cards assignment and getting it to deal... Roedy Green <see_website@mindprod.com.invalid> - 2014-08-04 18:43 -0700
    Re: Help with Deck of cards assignment and getting it to deal... "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-08-05 11:19 +0100
      Re: Help with Deck of cards assignment and getting it to deal... "Chris Uppal" <chris.uppal@metagnostic.REMOVE-THIS.org> - 2014-08-05 11:28 +0100
  Re: Help with Deck of cards assignment and getting it to deal... lipska the kat <lipskathekat@example.com> - 2014-08-31 17:31 +0100

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