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Groups > comp.lang.c > #112054 > unrolled thread
| Started by | Steve Keller <keller@no.invalid> |
|---|---|
| First post | 2017-06-12 18:34 +0200 |
| Last post | 2017-06-13 12:13 -0400 |
| Articles | 2 on this page of 42 — 13 participants |
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Hexadecimal float constants Steve Keller <keller@no.invalid> - 2017-06-12 18:34 +0200
Re: Hexadecimal float constants "James R. Kuyper" <jameskuyper@verizon.net> - 2017-06-12 12:44 -0400
Re: Hexadecimal float constants supercat@casperkitty.com - 2017-06-12 10:54 -0700
Re: Hexadecimal float constants Keith Thompson <kst-u@mib.org> - 2017-06-12 11:26 -0700
Re: Hexadecimal float constants bartc <bc@freeuk.com> - 2017-06-12 19:38 +0100
Re: Hexadecimal float constants scott@slp53.sl.home (Scott Lurndal) - 2017-06-12 18:45 +0000
Re: Hexadecimal float constants Robert Wessel <robertwessel2@yahoo.com> - 2017-06-12 13:54 -0500
Re: Hexadecimal float constants bartc <bc@freeuk.com> - 2017-06-12 20:40 +0100
Re: Hexadecimal float constants Keith Thompson <kst-u@mib.org> - 2017-06-12 13:06 -0700
Re: Hexadecimal float constants supercat@casperkitty.com - 2017-06-12 13:37 -0700
Re: Hexadecimal float constants bartc <bc@freeuk.com> - 2017-06-12 22:22 +0100
Re: Hexadecimal float constants Keith Thompson <kst-u@mib.org> - 2017-06-12 16:01 -0700
Re: Hexadecimal float constants supercat@casperkitty.com - 2017-06-12 16:36 -0700
Re: Hexadecimal float constants jameskuyper@verizon.net - 2017-06-12 12:39 -0700
Re: Hexadecimal float constants bartc <bc@freeuk.com> - 2017-06-12 18:42 +0100
Re: Hexadecimal float constants Thomas David Rivers <rivers@dignus.com> - 2017-06-12 17:27 -0400
Re: Hexadecimal float constants "James R. Kuyper" <jameskuyper@verizon.net> - 2017-06-12 18:03 -0400
Re: Hexadecimal float constants bartc <bc@freeuk.com> - 2017-06-12 23:31 +0100
Re: Hexadecimal float constants Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-06-13 00:10 +0100
Re: Hexadecimal float constants jacobnavia <jacob@jacob.remcomp.fr> - 2017-06-13 01:33 +0200
Re: Hexadecimal float constants Ben Bacarisse <ben.usenet@bsb.me.uk> - 2017-06-13 01:10 +0100
Re: Hexadecimal float constants supercat@casperkitty.com - 2017-06-12 16:01 -0700
Re: Hexadecimal float constants Keith Thompson <kst-u@mib.org> - 2017-06-12 17:00 -0700
Re: Hexadecimal float constants supercat@casperkitty.com - 2017-06-13 07:51 -0700
Re: Hexadecimal float constants Keith Thompson <kst-u@mib.org> - 2017-06-13 09:17 -0700
Re: Hexadecimal float constants bartc <bc@freeuk.com> - 2017-06-13 17:45 +0100
Re: Hexadecimal float constants Keith Thompson <kst-u@mib.org> - 2017-06-13 11:58 -0700
Re: Hexadecimal float constants supercat@casperkitty.com - 2017-06-13 12:57 -0700
Re: Hexadecimal float constants Keith Thompson <kst-u@mib.org> - 2017-06-13 13:01 -0700
Re: Hexadecimal float constants bartc <bc@freeuk.com> - 2017-06-13 22:11 +0100
Re: Hexadecimal float constants Keith Thompson <kst-u@mib.org> - 2017-06-13 14:22 -0700
Re: Hexadecimal float constants "James R. Kuyper" <jameskuyper@verizon.net> - 2017-06-13 17:43 -0400
Re: Hexadecimal float constants Keith Thompson <kst-u@mib.org> - 2017-06-13 14:48 -0700
Re: Hexadecimal float constants bartc <bc@freeuk.com> - 2017-06-13 23:03 +0100
Re: Hexadecimal float constants GOTHIER Nathan <nathan.gothier@gmail.com> - 2017-06-14 01:30 +0200
Re: Hexadecimal float constants supercat@casperkitty.com - 2017-06-13 12:24 -0700
Re: Hexadecimal float constants jacobnavia <jacob@jacob.remcomp.fr> - 2017-06-13 21:52 +0200
Re: Hexadecimal float constants Keith Thompson <kst-u@mib.org> - 2017-06-13 13:12 -0700
Re: Hexadecimal float constants supercat@casperkitty.com - 2017-06-13 16:18 -0700
Re: Hexadecimal float constants Ike Naar <ike@iceland.freeshell.org> - 2017-06-14 21:28 +0000
Re: Hexadecimal float constants supercat@casperkitty.com - 2017-06-12 15:21 -0700
Re: Hexadecimal float constants Thomas David Rivers <rivers@dignus.com> - 2017-06-13 12:13 -0400
Page 3 of 3 — ← Prev page 1 2 [3]
| From | supercat@casperkitty.com |
|---|---|
| Date | 2017-06-12 15:21 -0700 |
| Message-ID | <134a2a4f-7eb9-4054-916b-f4c694c1d7cb@googlegroups.com> |
| In reply to | #112089 |
On Monday, June 12, 2017 at 4:26:41 PM UTC-5, Thomas David Rivers wrote: > >I read in the thread "High quality resources for learning modern C?" > >that 0x1234e-1 is an illegal preprocessing token, and in fact, gcc and > >clang refuse it: > > > > xf.c:3:9: error: invalid suffix "-1" on integer constant > > int x = 0x1234e-1; > > > > > > > > Are we sure those compilers are correct? > > Why isn't this the same as this declaration: > > int x = 0x1234e - 1 ; > > (with extra spaces to denote the C constants/expression I see there.) > > In looking at the standard - I don't see the error the compilers are > reporting. > That looks like a bug in the compilers? The authors of the C Standard define the concept of a "preprocessing number" which is supposed to treat exponential-format numbers as a single token, and did so in a way that treats *any* sequence containing a digit 0-9, zero or more characters from the set [0-9A-Za-z], an E or e, a plus sign, and more characters from the set [0-9A-za-z], as a single token. The claimed motivation for doing so is to make things easier for compilers, even though many compilers that preceded the Standard used parsing strategies that made it easier to treat 0x1E + 4 as three tokens than to treat it as one. There is nothing in the rationale that suggests that the authors would regard a compiler that couldn't accept 0x1E+4 in that fashion would be in any way more useful than one that could, but it has become fashionable for compilers to go out of their way to reject such expressions.
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| From | Thomas David Rivers <rivers@dignus.com> |
|---|---|
| Date | 2017-06-13 12:13 -0400 |
| Message-ID | <59400F21.1040908@dignus.com> |
| In reply to | #112089 |
Thomas David Rivers wrote: > >> > > Are we sure those compilers are correct? > > Duh - I'm not sure what I was thinking when I wrote that... Nevermind :-) - Dave Rivers - -- rivers@dignus.com Work: (919) 676-0847 Get your mainframe programming tools at http://www.dignus.com
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