Groups > comp.lang.java.programmer > #4025

Re: Java puzzler

From	markspace <-@.>
Newsgroups	comp.lang.java.programmer
Subject	Re: Java puzzler
Date	2011-05-12 14:32 -0700
Organization	A noiseless patient Spider
Message-ID	<iqhjks$798$1@dont-email.me> (permalink)
References	(2 earlier) <alpine.DEB.2.00.1105112141410.27211@urchin.earth.li> <I6SdnROEzeMni1bQnZ2dnUVZ_sKdnZ2d@earthlink.com> <alpine.DEB.2.00.1105122029030.7602@urchin.earth.li> <-8mdnSRPEIdA21HQnZ2dnUVZ_j2dnZ2d@earthlink.com> <iqhhim$blg$4@speranza.aioe.org>

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>> On 5/12/2011 1:38 PM, Tom Anderson wrote:
>>> Instead, all arithmetic operations, and all casts, should throw
>>> an exception if they overflow.

Yes!

> On 12/05/2011 4:45 PM, Patricia Shanahan wrote:
>>
>> If we were starting from scratch, that would be an option. As it
>> is, it would break far too much code to be possible as a change to
>> the existing language.

I think, but I'm not sure, arithmetic overflow detection could be made 
an optional keyword.  Thus, new code could have the benefit of overflow 
detection while existing code would be able to use the current semantics.

>> To do that effectively you need a full set of signed and unsigned
>> data types, or, better still, arithmetic types with arbitrary value
>> ranges.

I'm not sure I understand this bit.

On 5/12/2011 1:56 PM, Nancy 3 wrote:
> There's also the minor little matter of number crunching performance
>  going straight to hell if every little add or multiply suddenly has
> some test-and-branch instructions added near it.

I believe arithmetic overflow could be handled efficiently at the 
machine level, without the need for an explicit test-and-branch.  I 
haven't looked at any datasheets recently, but I recall most CPUs have 
an option to trap, automatically, on overflow detection.

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Thread

Re: Java puzzler Gábor Bakos <aborgabor@gmail.com> - 2011-05-11 01:44 -0700
  Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-11 05:24 -0700
    Re: Java puzzler Tom Anderson <twic@urchin.earth.li> - 2011-05-11 21:57 +0100
      Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-11 16:07 -0700
        Re: Java puzzler Tom Anderson <twic@urchin.earth.li> - 2011-05-12 21:38 +0100
          Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-12 13:45 -0700
            Re: Java puzzler Nancy 3 <n3@gmai1.c0m> - 2011-05-12 16:56 -0400
              Re: Java puzzler markspace <-@.> - 2011-05-12 14:32 -0700
                Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-12 16:05 -0700
                Re: Java puzzler markspace <-@.> - 2011-05-12 17:40 -0700
                Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-12 18:18 -0700
                Re: Java puzzler markspace <-@.> - 2011-05-12 19:26 -0700
                Re: Java puzzler Tom Anderson <twic@urchin.earth.li> - 2011-05-14 10:18 +0100
                Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-14 08:09 -0700
                Re: Java puzzler Lew <noone@lewscanon.com> - 2011-05-14 13:00 -0400
                Re: Java puzzler Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-05-14 15:08 -0400
                Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-14 13:25 -0700
                Re: Java puzzler markspace <-@.> - 2011-05-14 08:46 -0700
                Re: Java puzzler Spock <spock@starfleet.ufp> - 2011-05-14 19:33 -0400
                Re: Java puzzler Tom Anderson <twic@urchin.earth.li> - 2011-05-15 00:41 +0100
                Re: Java puzzler markspace <-@.> - 2011-05-14 18:35 -0700
                Re: Java puzzler Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-05-14 23:43 -0400
                Re: Java puzzler Tom Anderson <twic@urchin.earth.li> - 2011-05-15 11:16 +0100
                Re: Java puzzler markspace <-@.> - 2011-05-15 05:40 -0700
                Re: Java puzzler Tom Anderson <twic@urchin.earth.li> - 2011-05-15 15:23 +0100
                Re: Java puzzler markspace <-@.> - 2011-05-15 08:09 -0700
                Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-15 07:37 -0700
                Re: Java puzzler markspace <-@.> - 2011-05-15 08:00 -0700
                Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-15 08:16 -0700
                Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-15 07:35 -0700
                Re: Java puzzler markspace <-@.> - 2011-05-15 08:11 -0700
                Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-15 08:15 -0700
                Re: Java puzzler Lew <noone@lewscanon.com> - 2011-05-15 13:11 -0400
                Re: Java puzzler Nancy 3 <n3@gmai1.c0m> - 2011-05-12 20:47 -0400
                Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-12 18:00 -0700
                Re: Java puzzler markspace <-@.> - 2011-05-12 18:01 -0700
                Re: Java puzzler Nancy 3 <n3@gmai1.c0m> - 2011-05-12 21:22 -0400
                Re: Java puzzler Patricia Shanahan <pats@acm.org> - 2011-05-12 18:32 -0700
                Re: Java puzzler Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-05-12 22:34 -0400
              Re: Java puzzler Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-05-12 22:27 -0400
      Re: Java puzzler "John B. Matthews" <nospam@nospam.invalid> - 2011-05-12 00:28 -0400
      Re: Java puzzler Joshua Cranmer <Pidgeot18@verizon.invalid> - 2011-05-12 10:33 -0400
  Re: Java puzzler Lew <noone@lewscanon.com> - 2011-05-11 09:12 -0400
  Re: Java puzzler Lew <noone@lewscanon.com> - 2011-05-11 09:13 -0400
  Re: Java puzzler markspace <-@.> - 2011-05-11 08:00 -0700

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