can somebody please expand on the O(1) req on operators? O(1) as a function of what? Is a C impl on x86 for example is not complaint if for example the expr:
' x >>= c; ' is O(c) ? (since x86 shl reg,cl is O(cl)), how about mult/div? --Oyd11
Do you think it's good to use Evolution for writing down the changes, or K and R C will suffice? Thanks, Uriyan
Actually I don't think either topic deserves a sub-page. I think a section on the main page would do. --drj
- === Eccentricity ===
- In C, the months of the year are numbered wrong. They are all low by 1. For example: January is month 0. December is month 11. This is not an obvious problem to English-speakers, but if your native language uses numbers to name the months of the year...
Numbering from 0 is not eccentricity. It's how computers think. --Taw
- That also has nothing at all to do with the C language, but with the standard libraries--that distinction should be made. --LDC
I don't even think thats an eccentricity since its fairly common in programming to do it that way --Alan D
- Fairly common today, but it wasn't in the Good Old Days. That makes it a fad, albeit a fairly long running one. Hint: make a list of languages since Day 1 and see when numbering from 0 began. GregLindahl
Java uses the same numbering scheme. Possibly because there is a zero-based array of month names. Although numbering from zero in both C and Java is more of a convenience for the routines that perform array handling than anything else. If your array starts at ___location AC00, the address of the 0th element is AC00, the address of element 1 is AC00 + element_length, the address of the 2nd element is AC00 + 2 * element_length, and so on. I prefer to start at element 1, but we're all pretty much stuck with the convention. (Perhaps I'll step up and start writing about software engineering, something I actually have some expertise in.) Ed Poor
Example date (works for C and Java): May 29
Month=4, day=29
Why is the month shifted but not the day of the month? Besides, if it is "the month is not a number", you deserve a slap in the face from your Korean (or Japanese or Chinese) secretary; ask her about it! In all these languages, May is literally "five month". (I think.) -- Juuitchan
Yes, but you'd translate it into english as 'month five' if you didn't want to use the name - 五月 is how you'd write it in chinese characters.
If you want to blame someone for the system in use, I'd suggest starting with the Jesuits, who as the scientific wing of the catholic church spread clockwork and steel cannons across much of asia. They also brought their date systems with them, which is why a 24 hour clock and seven day week is pretty much universally accepted.
The difference between day and month in terms of indexing can be reduced to that of the difference between both nominal and cardinal values and ordinal values.
The system we use uses nominal values for months, and ordinal values for days and years. It should probably use ordinal values for the lot. Note, though that Korean (and I expect Japanese and Chinese) uses cardinal values, rather than ordinal values for month. O-Ueol (五月) vs' O-Beon-JJae-Ueol (五番째月), except that normally the chinese characters aren't used in the second case.
This was probably far more than you wanted to know, but the point is that given that there are trivial mappings between these forms, the particular representation format chosen isn't that big a deal.
If you want to see _real_ problems with computational notions of time, I'd refer you to 'A Long, Painful History of Time' (Erik Naggum [1]).
-- 203.231.161.129
The claim that C is the dominant microcomputer applications language is now somewhat dubious, IMHO. In the Windows world, it's probably a toss-up between Microsoft's C++ and Visual Basic, I'd guess. C still rules for embedded systems (that is, the ones not written in Assembler), in the Unix world (particularly for apps that don't have a GUI), and people who can't be bothered remembering C++'s arcane semantics for multiple inheritance and operator overloading :) --Robert Merkel
- How much Visual C++ is actually plain C with a tiny bit of C++ here and there? GregLindahl
- Good question, but one which I don't know the answer to. The only big Windows development project I ever saw was in "real" C++, with a class hierachy etc. etc. It was an absolute PITA to work with, though - in the end I just gave up and wrote the code I needed by monitoring a socket interface this code had with a socket monitor I ginned up with Cygwin.--Robert Merkel
- Any windows programming that uses MFC is making extensive use of C++, just by virtue of modelling windows in terms of objects. I think that's actually a good portion of Visual C++ programming.
- Yup. Visual C++ (the language) is mostly C++. Of course, the product Microsoft Studio, Visual C++, has compilers for both the language C and the language C++ (and options to turn microsoft extensions to both of those language on or off). Secretly the two compilers are the same, but accepting different input languages.
Recent stats of what percent of code in RedHat distro is written in which programing language, clearly shows that C is dominant, at least on Unices. It's very probable that C++ is much more popular on Windoze world, but I seriously doubt that many apps are written in VB. --Taw
Are we talking commercial apps or what? VB is insanely popular inside IT departments, but for commercial software its always been limited by that damn runtime DLL. C++ seems to rule commercial apps. As for C, its probly less common on windows than C++ at this point.
How can I learn C++ Vera Cruz
It would be nice to have links to an online manual and online tutorials. There probably are some with under the GNU Free Documentation License. --Hirzel
comp.lang.c (a wonderful resource for C, btw -- some very competent people there) recommends Tom Torfs' tutorial at http://www.geocities.com/tom_torfs/c.html and Steve Summit's class notes at http://www.eskimo.com/~scs/cclass/cclass.html.
Honestly, most online tutorials for C are terrible and demonstrate that the author has little clue about the actual C standard. --mgmei
Moved from article:
- C is a high level language, meaning that the source code of a program can be written without detailed knowledge of the computer's CPU type. Before the program can be used, the source code must be translated into the required machine language by a compiler. In contrast, programs written in an assembly language can only be run on one type of CPU.
- (The above definition of high level language is not meaningful. Consider the evolution of the x86 instruction set toward virtual machinehood. Does this mean that x86 assembly is a high level language?)
I'm not sure what 203.231.161.129 means about "virtual machinehood", but I can see that under this definition, x86 assembly language could be considered a high level language due to the existence of emulators. -- Tim Starling 07:54 26 Jun 2003 (UTC)
Modern x86 implementations are more and more moving toward risc cores running virtual machines (in microcode or whatever) which provide x86 compatible instruction sets. Hyperthreading for example, is a case of attempting to exploit such an underlying architecture without affecting the definition of the x86 machine (ie, mapping many registers to the x86's few, so that you can increase some hparallelism).
In this regard the x86 architecture is shifting toward defining a virtual machine, much like JVM, rather than specifying a hardware cpu. Not that there is a meaningful distinction in any case.
Likewise, we can see C programs running in a virtual machine defined by the C standard, and supported by the runtime structure of the binary produced.
High and low level are fundamentally ideological terms, and have almost no objective meaning, nor objective definition what-so-ever. So far the only meaningful definition of level that I've found has been in terms of 'the ability to express invariant structure' with more being higher level. Note that by this definition, python ends up being only slightly higher than assembly, since it has almost no ability to define invariant structure.
I wish people would stop using these terms, anyhow, as they are very silly.
-- 203.231.161.129
The page says the language B got its name from BCPL. But Wombat's encyclopedia says this is wrong. It says "B had nothing to do with BCPL. B was in fact a revision of an earlier language, bon, named after Ken Thompson's wife, Bonnie."
Jay 22:44 5 Jul 2003 (UTC)
I see that the spelling "behaviour" in place of "behavior" is used in the C programming language article. My copy of the C Standard uses "behavior". Should this Wikiopedia article use spelling consistent with the C language Standard? Or, maybe there is more than one English language version of the C Standard? LarryW 01:57, 3 Aug 2003 (UTC)
- I think we should use the spelling of the ISO C standard for technical terms such as undefined behavior and unspecified behavior. I'm pretty sure that there's only one official English-language version of the ISO standard (at least for C99). --Zundark 10:31, 3 Aug 2003 (UTC)
- OK -- LarryW 23:16, 3 Aug 2003 (UTC)
There were no responses to my comment of 5th July suggesting B was a revision of bon and not BPCL as claimed. Hence I've made the change in the main page.
Jay 11:42, 10 Aug 2003 (UTC)
- Jay,see http://cm.bell-labs.com/cm/cs/who/dmr/chist.html. I think the language there implies that C descended from BCPL, not bon. (At the end of the History: the setting section).
- The line is not conclusive enough. Ritchie says "most probably", and also does not claim that the Bon theory is wrong. Moroever, the creator of "B" is Ken Thompson and the Bon theory is taken from a paper/book (Thompson 69) written by him (this is mentioned in the same line). Jay 18:35, Aug 20, 2003 (UTC)
It would be nice to have a paragraph about other important libraries besides the standard C library.
- Which other libraries?
Maybe glib, for instance. -- Taku 01:38, Nov 16, 2003 (UTC)
- By 1973, the C language had become powerful enough that most of the kernel of the Unix operating system was reimplemented in C, perhaps following the examples of the Multics system (implemented in PL/I), Tripos (implemented in BCPL), and perhaps others.
But according to the TRIPOS page, TRIPOS was was developped in 1978, five years after Unix was re-implemented in C. Which is right? -- Khym Chanur
I would like to split off anatomy of C section to its own aritcle and merge ANSI C and ANSI C standard library with this article. It is more relevant to discuss history or standards than syntax details in this article, I think. Any thought or objection is welcomed. -- Taku 01:38, Nov 16, 2003 (UTC)
" During the late '70s, C began to replace BASIC as the standard microcomputer language," : BASIC was never a "Standard" programming language in the '70s. It was a teaching language. Only with the rise of MS's Visual basic did it become a real-world language, and it's still very limited in its application (it's mostly useful for GUIs). orthogonal 04:01, 26 Nov 2003 (UTC)
- I think it depends on how you interpret the word "standard". If you mean "defined by formal written standards", then I'd agree that BASIC is not, and has never been, a standard language. But I don't think that's what's meant here. During the late 1970s, microcomputers were typically programmed in either assembly or BASIC - consider as examples the MITS Altair 8800 & 680, Commodore Pet, TRS-80, Apple 2, VIC-20 and Commodore 64. I'm rather suspicious of the IBM(1981) reference, though: I was using IBM PC's in 1989 and there wasn't a hint of C on them. -- Ortonmc 04:15, 26 Nov 2003 (UTC)
- For amateur end users, perhaps; but I was taking it to men that most applications were written in BASIC, which I find dubious. orthogonal 04:26, 26 Nov 2003 (UTC)
I have removed the "standard" comment, since it is ambiguous. Lirath Q. Pynnor
'C++ (thus avoiding the issue of whether the successor to "B" and "C" should be "D" or "P".)' Why would it be "P"? -- Ortonmc 04:15, 26 Nov 2003 (UTC)