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IWETHEY Home / IWETHEY Board / Theory and Practice of Programming Forum / Wasn't trying to piss you off...
Post #171,339
by hnick
8/27/04 4:06:40 PM
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New Wasn't trying to piss you off...
From my point of view, hex and octal are just more convienient ways to write binary.
Hex/octal/binary numbers are not negative without some convention to make them so. This varies.
The C language, and those that borrowed from it, make the tacit assumption that the high bit indicates a negative number unless it is declared unsigned, in which case it is just a binary number in the range of 0 - UINT_MAX (from limits.h) I don't know of any languages where you can write -0x123 for a negative hex number.
I should mention that I am not particularly a language pedant. I currently use C/C++ for some application work and drivers, I write firmware for a propriatary processor in a much modified, self maintained assembler, and do scripting in perl as necessary. Plus whatever needs be done. I'm not a purist. I really wasn't trying to pick nits.
Post #171,760
by jb4
Picture of jb4
8/30/04 5:51:55 PM
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New Interesting assumption:
The C language, and those that borrowed from it, make the tacit assumption that the high bit indicates a negative number unless it is declared unsigned...

An interesting assumption. I don't believe C makes that assumption at all. The underlying hardware makes that assumption, because that's simply the way it works. C (the language) doesn't care. An implementation of C cares, because it has to map tokens that represent negative values to the actual binary representation of the value.

Now it has been several Decades since I saw a machine that doesn't uset two's complement arithmetic. The first one was an NCR 315 that our local bank used when I was in high school in 1968...It was a DECIMAL machine that used XS-3 notation internally. the last one I saw was a CDC Star, which is a 60-bit (!) machine that used ones complement artihmetic...which has a unique value for negative zero. The NCR machine antedated C by something like a decade, but were a C compiler to exist for that machine, it could not assume the high-order bit of a value made it negative.
jb4
shrub\ufffdbish (Am., from shrub + rubbish, after the derisive name for America's 43 president; 2003) n. 1. a form of nonsensical political doubletalk wherein the speaker attempts to defend the indefensible by lying, obfuscation, or otherwise misstating the facts; GIBBERISH. 2. any of a collection of utterances from America's putative 43rd president. cf. BULLSHIT
     What is with gcc, anyway?!? - (jb4) - (52) - Aug. 26, 2004, 06:07:59 PM EDT
         What is typeof(0x80000000)? - (ChrisR) - (7) - Aug. 26, 2004, 06:25:16 PM EDT
             right, add an L -NT - (deSitter) - (6) - Aug. 26, 2004, 06:30:08 PM EDT
                 Ain't that a UL - (ChrisR) - (5) - Aug. 26, 2004, 06:34:49 PM EDT
                     This is why C is sometimes called "high-level assembler." - (static) - (1) - Aug. 26, 2004, 09:11:16 PM EDT
                         Re: This is why C is sometimes called "high-level assembler. - (jb4) - Aug. 27, 2004, 09:35:47 AM EDT
                     Actually, that would be a U (or u) - (jb4) - (2) - Aug. 27, 2004, 09:43:22 AM EDT
                         What about casting the values? - (ChrisR) - (1) - Aug. 31, 2004, 11:34:46 AM EDT
                             Yes, that was the solution I used - (jb4) - Aug. 31, 2004, 11:55:24 AM EDT
         Re: What is with gcc, anyway?!? - (lordbeatnik) - (3) - Aug. 26, 2004, 11:05:40 PM EDT
             I guess... - (jb4) - (2) - Aug. 27, 2004, 09:39:19 AM EDT
                 If there was no ambiguity... - (lordbeatnik) - (1) - Aug. 27, 2004, 06:51:20 PM EDT
                     For the next set of standards? - (jb4) - Aug. 30, 2004, 05:29:20 PM EDT
         Hex constants are assumed to be positive - (Arkadiy) - (36) - Aug. 27, 2004, 11:32:17 AM EDT
             Re: Hex constants are assumed to be positive - (jb4) - (35) - Aug. 27, 2004, 01:15:45 PM EDT
                 Setting the high bit is processor dependent. - (hnick) - (34) - Aug. 27, 2004, 01:27:28 PM EDT
                     OK, then the standard should be saying - (Arkadiy) - (33) - Aug. 27, 2004, 01:53:36 PM EDT
                         No I actually write code based on them - (jb4) - (30) - Aug. 27, 2004, 02:27:25 PM EDT
                             Ignore them and use my common sence -NT - (Arkadiy) - (29) - Aug. 27, 2004, 03:24:32 PM EDT
                                 I'll bet debugging your code is a real joy... - (jb4) - (28) - Aug. 30, 2004, 05:29:56 PM EDT
                                     Nope - (Arkadiy) - (27) - Aug. 31, 2004, 10:04:06 AM EDT
                                         And so tell me, O Oracle of Common Sence [sic] - (jb4) - (26) - Aug. 31, 2004, 11:04:10 AM EDT
                                             offensive foul, ball to Ark - (deSitter) - (3) - Aug. 31, 2004, 11:10:45 AM EDT
                                                 Rest assured, - (Arkadiy) - (1) - Aug. 31, 2004, 11:17:52 AM EDT
                                                     :) ok -NT - (deSitter) - Aug. 31, 2004, 11:25:55 AM EDT
                                                 OK, OK... - (jb4) - Aug. 31, 2004, 11:26:59 AM EDT
                                             Well, while the tone is disagreable, the question is - (Arkadiy) - (21) - Aug. 31, 2004, 11:14:05 AM EDT
                                                 Point missed. - (jb4) - (20) - Aug. 31, 2004, 11:25:35 AM EDT
                                                     If C were sane, TRUE = -1 and problem vanishes -NT - (deSitter) - (7) - Aug. 31, 2004, 11:26:40 AM EDT
                                                         Ermm...say What? - (jb4) - (2) - Aug. 31, 2004, 11:28:42 AM EDT
                                                             Re: Ermm...say What? - (deSitter) - (1) - Aug. 31, 2004, 11:37:26 AM EDT
                                                                 Much like Jewish law - (Arkadiy) - Aug. 31, 2004, 11:43:34 AM EDT
                                                         So you prefer how VB does it?? -NT - (ben_tilly) - (3) - Aug. 31, 2004, 01:01:31 PM EDT
                                                             Point: Ben... -NT - (jb4) - Aug. 31, 2004, 01:04:18 PM EDT
                                                             How it used to do it. - (ChrisR) - (1) - Aug. 31, 2004, 01:47:19 PM EDT
                                                                 Hehee! - (jb4) - Aug. 31, 2004, 03:18:32 PM EDT
                                                     Why do you expect hex to be treated differently from decimal - (Arkadiy) - (11) - Aug. 31, 2004, 11:32:44 AM EDT
                                                         Re: Why do you expect hex to be treated differently - (deSitter) - Aug. 31, 2004, 11:42:16 AM EDT
                                                         Man, that's a good question! - (jb4) - Aug. 31, 2004, 12:37:46 PM EDT
                                                         Now that's clarity! -NT - (a6l6e6x) - (8) - Aug. 31, 2004, 04:42:17 PM EDT
                                                             Nope, it's bad math - (deSitter) - (7) - Aug. 31, 2004, 05:00:03 PM EDT
                                                                 But, counters of real things don't need negative values. -NT - (a6l6e6x) - (6) - Aug. 31, 2004, 05:19:13 PM EDT
                                                                     I'd like to add a negative number of votes for Bush. ;-) -NT - (ben_tilly) - (1) - Aug. 31, 2004, 05:20:08 PM EDT
                                                                         That only works on Diebold machines. :) -NT - (a6l6e6x) - Aug. 31, 2004, 05:23:34 PM EDT
                                                                     Certainly - (deSitter) - (3) - Aug. 31, 2004, 05:21:51 PM EDT
                                                                         "Expressive", not "pithy" :) - (Arkadiy) - (2) - Aug. 31, 2004, 06:59:29 PM EDT
                                                                             Re: "Expressive", not "pithy" :) - (deSitter) - (1) - Aug. 31, 2004, 07:03:32 PM EDT
                                                                                 Dunno. - (Arkadiy) - Sept. 1, 2004, 09:33:56 AM EDT
                         Wasn't trying to piss you off... - (hnick) - (1) - Aug. 27, 2004, 04:06:40 PM EDT
                             Interesting assumption: - (jb4) - Aug. 30, 2004, 05:51:55 PM EDT
         Hmm...while the datatype will be first reached, - (Simon_Jester) - (1) - Aug. 27, 2004, 05:35:03 PM EDT
             True, but... - (jb4) - Aug. 30, 2004, 05:55:52 PM EDT
         Re: What is with gcc, anyway?!? - (gdaustin) - Aug. 31, 2004, 11:10:58 PM EDT

Up is down. Left is right. Black licorice tastes good.
182 ms