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Re: IE and IEE 754

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Ben Bacarisse <ben.usenet@bsb.me.uk> wrote on 29 aug 2014 in 
comp.lang.javascript:

> "Evertjan." <exxjxw.hannivoort@inter.nl.net> writes:
> 
>> Ben Bacarisse <ben.usenet@bsb.me.uk> wrote on 28 aug 2014 in 
>> comp.lang.javascript:
>>> You mean "yes, but..." surely?  You did not say that that they cannot be
>>> *trusted* to be exact, you said that they can't ever be exact.
>>
>> Wow, are you still in kindergarten?
> 
> I'd like to try to unravel this.  I don't think I am wrong to say that
> 0.5 can be converted to a binary floating point value exactly, and I
> don't think you disagree on that point, but can you see that what you
> wrote:
> 
>   "... the binary converions of floting point fractional decimal values
>   NEVER can be right"
> 
> does seem to suggest otherwise?  I even suggested that there was a
> communication problem:
> 
>   "What about 0.5 or 0.25?  Why can't these ever be right?  Did you mean
>   that *all* decimal fractions can't be correctly converted?  That's
>   certainly the case.  The way you worded it sounds like none of them
>   can be."
> 
> But that was not, it seems, what you wanted to say.
> 
> When you rejected my examples of 0.5 and 0.25 you said the conversion
> could not be trusted to be exact (correct me, if I've misunderstood that
> as well).  That sounded exactly like a "yes they can be exact, but they
> can't be trusted to be exact". 

"Fixed point decimal <input> strings" can incidentally be exact, like 
'27.00', but the whole idea is the you as a programmer, when allowing for 
fractional input strings[!], don't know beforehand what number will be 
inputted, and an incidental input of '0.50' cannot be taken as exact, 
because you would have to make an array of exact decimal values, and still 
have the rest of the possibilities delt with as non-exact.

Therefore your example of 0.5 is childish, as it does not seriously address 
the problem of binary conversion in programmes.

> If you weren't saying "yes, but" what
> were you saying?  "No, they can't be exact and in addition they can be
> trusted to be exact"?  That doesn't sound right.

Indeed so, I cannot controll the way it sounds to you.

However, when programming money variables, better take it that these "fixed 
point decimal input strings" are NOT exact when stored and retrieved using 
binary conversion, like sailing the 7 seas without any navigational 
instrument does not get you from Amsterdam to New York, even if incidentally 
you might.
 
> If you think my pointing this out was childish, or the way in which I
> did so was childish, then I am genuinely sorry about that.  I certainly
> don't want to appear childish, but I am now a little lost about what it
> is you are saying.

Okay. I hope I am claring things up now.

-- 
Evertjan.
The Netherlands.
(Please change the x'es to dots in my emailaddress)

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IE and IEE 754 RobG <rgqld@iinet.net.au> - 2014-08-27 22:44 +1000
  Re: IE and IEEE 754 John Harris <niam@jghnorth.org.uk.invalid> - 2014-08-27 15:23 +0100
  IE and IEEE 754 (was: IE and IEE 754) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-08-27 20:59 +0200
  Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-27 22:04 +0200
    Re: IE and IEE 754 "Christoph M. Becker" <cmbecker69@arcor.de> - 2014-08-27 22:35 +0200
      Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-28 00:07 +0200
        Re: IE and IEE 754 "Christoph M. Becker" <cmbecker69@arcor.de> - 2014-08-28 00:47 +0200
          Re: IE and IEE 754 Gene Wirchenko <genew@telus.net> - 2014-08-28 10:13 -0700
            Re: IE and IEE 754 "Christoph M. Becker" <cmbecker69@arcor.de> - 2014-08-28 22:15 +0200
              Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-28 23:24 +0200
                Re: IE and IEE 754 "Christoph M. Becker" <cmbecker69@arcor.de> - 2014-08-29 01:16 +0200
                Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-29 09:32 +0200
      Re: IE and IEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-27 23:59 +0100
        Re: IE and IEE 754 "Christoph M. Becker" <cmbecker69@arcor.de> - 2014-08-28 02:55 +0200
          Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-28 09:50 +0200
            Re: IE and IEE 754 Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-08-28 12:21 +0200
              Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-28 13:42 +0200
          Re: IE and IEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-28 11:27 +0100
            Re: IE and IEE 754 Gene Wirchenko <genew@telus.net> - 2014-08-28 10:16 -0700
              Re: IE and IEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-29 00:04 +0100
                Re: IE and IEE 754 Gene Wirchenko <genew@telus.net> - 2014-08-29 11:15 -0700
                IEEE 754 (was: IE and IEE 754) "Christoph M. Becker" <cmbecker69@arcor.de> - 2014-08-29 21:30 +0200
                Re: IEEE 754 (was: IE and IEE 754) Gene Wirchenko <genew@telus.net> - 2014-09-02 11:22 -0700
                Re: IE and IEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-29 20:42 +0100
                IEEE 754 (was: IE and IEE 754) "Christoph M. Becker" <cmbecker69@arcor.de> - 2014-08-29 23:29 +0200
                Re: IEEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-29 23:27 +0100
                Re: IE and IEE 754 Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-08-30 20:32 +0100
                Re: IE and IEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-31 01:04 +0100
                IE and IEEE 754 Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-09-01 23:05 +0100
    Re: IE and IEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-28 00:05 +0100
      Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-28 08:56 +0200
        Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-28 09:51 +0200
          Re: IE and IEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-28 11:16 +0100
            Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-28 13:34 +0200
              Re: IE and IEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-28 23:41 +0100
                Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-29 09:09 +0200
                Re: IE and IEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-29 12:39 +0100
                Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-29 16:55 +0200
                Re: IE and IEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-29 18:28 +0100
                Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-30 00:37 +0200
                Re: IE and IEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-29 23:53 +0100
                Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-30 01:08 +0200
                Re: IE and IEE 754 Ben Bacarisse <ben.usenet@bsb.me.uk> - 2014-08-30 00:40 +0100
                Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-30 09:32 +0200
                Re: IE and IEE 754 Gene Wirchenko <genew@telus.net> - 2014-08-29 11:22 -0700
                Re: IE and IEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-30 00:14 +0200
  IE and IEEE 754 (was: IE and IEE 754) "Christoph M. Becker" <cmbecker69@arcor.de> - 2014-08-27 22:08 +0200
    Re: IE and IEEE 754 RobG <rgqld@iinet.net.au> - 2014-08-28 22:50 +1000
    Re: IE and IEEE 754 RobG <rgqld@iinet.net.au> - 2014-08-28 22:55 +1000
    Re: IE and IEEE 754 (was: IE and IEE 754) Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-08-28 21:50 +0100
      Re: IE and IEEE 754 (was: IE and IEE 754) "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-29 09:43 +0200
        Re: IE and IEEE 754 (was: IE and IEE 754) Denis McMahon <denismfmcmahon@gmail.com> - 2014-08-29 08:42 +0000
        Re: IE and IEEE 754 Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-08-30 16:24 +0200
          Re: IE and IEEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-30 17:08 +0200
            Re: IE and IEEE 754 Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-08-30 18:12 +0200
              Re: IE and IEEE 754 "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-08-30 18:32 +0200

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