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Re: [JLS] new long[0][ -1 ]

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On Fri, 10 Jul 2015 14:19:24 +0000, Andreas Leitgeb wrote:

> Eric Sosman <esosman@comcast-dot-net.invalid> wrote:
>>      You're welcome.  But contemplating the uses of an array with
>> fewer than zero elements has tied what remains of my brain in a knot
>> that may not dissolve until my brain itself does ...  :-)
> 
> Some class's constructor gets passed two ints meaning width and height
> of some rectangular grid. Currently, the only argument-sanitization is
> to create a two dimensional array with it. Any exceptions caused by bad
> arguments to "new int[ height ][ width ]" will be seen by client-code.
> 
> My concern was, that a negative width might pass undetected after a zero
> height.  As is now clear: it doesn't, so it's all fine for me.  I don't
> care what exceptions are thrown back for bogus arguments, as long as all
> bogosity ends in some exception right on the spot.
> 
>>      <off-topic> What use might we make of a minus-sized array?
>> Perhaps it could model the old joke about a biologist, an engineer, and
>> a mathematician at a sidewalk cafe.  They see two people enter a
>> building across the street, and a little later three people emerge.
>> "They have reproduced," says the biologist. "Observational error," says
>> the engineer. And the mathematician observes "If somebody now goes
>> inside, the building will be empty." </off-topic>
> 
> Too bad, arrays are fixed-size, so we cannot even add elements to make
> it zero-sized.  ;-)
>
Two features I'd have liked to see in Java are non-zero based arrays, e.g.
 int temperatureOcurrences[-40:55] and flexible array bounds, e.g
 int samples[0:flex]

Neither are new ideas, both dating from the '60s: Algol 60 had non-zero-
based fixed size arrays and Algol 68 implemented both concepts: both are 
useful in some circumstances as is multi-dimensional array slicing (Algol 
68 had that too).


-- 
martin@   | Martin Gregorie
gregorie. | Essex, UK
org       |

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[JLS] new long[0][ -1 ] Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2015-07-10 11:52 +0000
  Re: [JLS] new long[0][ -1 ] Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-07-10 08:02 -0400
    Re: [JLS] new long[0][ -1 ] Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2015-07-10 12:58 +0000
      Re: [JLS] new long[0][ -1 ] Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-07-10 09:45 -0400
        Re: [JLS] new long[0][ -1 ] Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2015-07-10 14:19 +0000
          Re: [JLS] new long[0][ -1 ] Martin Gregorie <martin@address-in-sig.invalid> - 2015-07-10 20:19 +0000
            Re: [JLS] new long[0][ -1 ] Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-07-10 16:43 -0400
              Re: [JLS] new long[0][ -1 ] Martin Gregorie <martin@address-in-sig.invalid> - 2015-07-10 22:24 +0000
                Re: [JLS] new long[0][ -1 ] Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-07-11 07:33 -0400
            Re: [JLS] new long[0][ -1 ] Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2015-07-10 21:17 +0000
              Re: [JLS] new long[0][ -1 ] Martin Gregorie <martin@address-in-sig.invalid> - 2015-07-10 22:29 +0000
            Re: [JLS] new long[0][ -1 ] Arne Vajhøj <arne@vajhoej.dk> - 2015-07-27 22:10 -0400
              Re: [JLS] new long[0][ -1 ] leif.roar@dimnakorr.com - 2015-07-28 01:53 -0500
                Re: [JLS] new long[0][ -1 ] Arne Vajhøj <arne@vajhoej.dk> - 2015-07-28 19:13 -0400
                Re: [JLS] new long[0][ -1 ] leif.roar@dimnakorr.com - 2015-07-28 21:50 -0500
              Re: [JLS] new long[0][ -1 ] Martin Gregorie <martin@address-in-sig.invalid> - 2015-07-28 11:13 +0000
                Re: [JLS] new long[0][ -1 ] Arne Vajhøj <arne@vajhoej.dk> - 2015-07-31 19:41 -0400
                Re: [JLS] new long[0][ -1 ] Martin Gregorie <martin@address-in-sig.invalid> - 2015-08-01 10:23 +0000
  Re: [JLS] new long[0][ -1 ] Joerg Meier <joergmmeier@arcor.de> - 2015-07-10 17:07 +0200
    Re: [JLS] new long[0][ -1 ] Andreas Leitgeb <avl@auth.logic.tuwien.ac.at> - 2015-07-10 18:10 +0000

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