Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The Unreasonable Effectiveness of C

damienkatz.net

Post reply on HN
Print view View original

101–110 of 394 posts

Re: The Unreasonable Effectiveness of C

#101

Post by hackinthebochs »

michaelochurch wrote: post #56

I'm a language design buff, so you might be able to guess my biases: FP is good, OO is bad, every language should have higher-order functions, yadda yadda. I finally decided to get a deeper knowledge of C, something I've been saying I "should do" for years. I'm learning it via Zed Shaw's Learn C The Hard Way and I'm very impressed by the language. It does what it does very well. I wouldn't use it for a complex web ap…

Interesting, I would have considered deep knowledge of C a prerequisite to being a language design buff. Did you have experience implementing languages?

Re: The Unreasonable Effectiveness of C

#102

Post by mjs »

pdw wrote: post #68
RodgerTheGreat wrote: post #58

Earlier quoted context omitted.

If you agree with Hans Boehm, "Threads Cannot be Implemented as a Library": http://www.hpl.hp.com/techreports/2004/HPL-2004-209.pdf

The C11 standard added concurrency primitives to the language.

Interesting. Do you know what the tool support is like? What compilers implement it, if debuggers support it, etc.

Re: The Unreasonable Effectiveness of C

#103

Post by looser »

DigitalJack wrote: post #74
madhadron wrote: post #53

Oh for heavens' sakes. Yet more ignorance. A more realistic view of C: - C is straightforward to compile into fast machine code...on a PDP-11. Its virtual machine does not match modern architectures very well, and its explicitness about details of its machine mean FORTRAN compilers typically produce faster code. The C virtual machine does not provide an accurate model of why your code is fast on a modern machine. The…

I'm pretty ignorant about this stuff, so please don't think I'm trolling. I'm confused when you speak of a virtual machine with regard to C... can you explain what you mean by this? I had to wikipedia the Burroughs machine. I guess the big deal is that it's a stack machine? It looks very interesting and I plan to read more about it. But I guess I don't understand why that is a hindrance to C. The JVM is a stack machi…

It may be the parent comment is referring to the Runtime-Library when using the term Virtual Machine.

Re: The Unreasonable Effectiveness of C

#104

Post by madhadron »

DigitalJack wrote: post #74
madhadron wrote: post #53

Oh for heavens' sakes. Yet more ignorance. A more realistic view of C: - C is straightforward to compile into fast machine code...on a PDP-11. Its virtual machine does not match modern architectures very well, and its explicitness about details of its machine mean FORTRAN compilers typically produce faster code. The C virtual machine does not provide an accurate model of why your code is fast on a modern machine. The…

I'm pretty ignorant about this stuff, so please don't think I'm trolling. I'm confused when you speak of a virtual machine with regard to C... can you explain what you mean by this? I had to wikipedia the Burroughs machine. I guess the big deal is that it's a stack machine? It looks very interesting and I plan to read more about it. But I guess I don't understand why that is a hindrance to C. The JVM is a stack machi…

The Burroughs was a stack machine, but that's only the beginning. Look at how it handled addressing hunks of memory. Bounds checked memory block references were a hardware type, and they were the only way to get a reference to a block of memory. So basically, null pointers didn't exist at the hardware level, nor out of bounds writes to arrays or strings. Similarly, code and data were distinguished in memory (by high order bits), so you couldn't execute data. It simply wasn't recognized as code by the processor. Also interesting, the Burroughs machines were built to use a variant of ALGOL 60 as both their systems programming language (as in, there wasn't an assembly language beneath it) and as their command language. The whole architecture was designed to run high level procedural languages.

C defines a virtual machine consisting of a single, contiguous block of memory with consecutive addresses, and a single core processor that reads and executes a single instruction at a time. This is not true of today's processors, thanks to multicores, multiple pipelines, and layers of cache.

Re: The Unreasonable Effectiveness of C

#105

Post by madhadron »

looser wrote: post #103
DigitalJack wrote: post #74

Earlier quoted context omitted.

I'm pretty ignorant about this stuff, so please don't think I'm trolling. I'm confused when you speak of a virtual machine with regard to C... can you explain what you mean by this? I had to wikipedia the Burroughs machine. I guess the big deal is that it's a stack machine? It looks very interesting and I plan to read more about it. But I guess I don't understand why that is a hindrance to C. The JVM is a stack machi…

It may be the parent comment is referring to the Runtime-Library when using the term Virtual Machine.

No, I am referring to the virtual machine defined by the C language.

Re: The Unreasonable Effectiveness of C

#106

Post by stephencanon »

madhadron wrote: post #53

Oh for heavens' sakes. Yet more ignorance. A more realistic view of C: - C is straightforward to compile into fast machine code...on a PDP-11. Its virtual machine does not match modern architectures very well, and its explicitness about details of its machine mean FORTRAN compilers typically produce faster code. The C virtual machine does not provide an accurate model of why your code is fast on a modern machine. The…

Fortran compilers sometimes produce faster code for a limited subdomain of problems because fortran's language semantics are less restrictive: all arrays are assumed to not alias and the compiler has more freedom to reassociate arithmetic and apply other unsafe arithmetic transformations that are disallowed by C's stricter model.

C compilers let you specify that you want similarly relaxed semantics via compiler flags and language keywords; however, they also allow the programmer to have stricter behavior when necessary, e.g. allowing one to operate on memory that may actually alias and still get correct behavior.

Re: The Unreasonable Effectiveness of C

#107

Post by madhadron »

_yosefk wrote: post #77
madhadron wrote: post #53

Oh for heavens' sakes. Yet more ignorance. A more realistic view of C: - C is straightforward to compile into fast machine code...on a PDP-11. Its virtual machine does not match modern architectures very well, and its explicitness about details of its machine mean FORTRAN compilers typically produce faster code. The C virtual machine does not provide an accurate model of why your code is fast on a modern machine. The…

The article argued that C was effective in practice, not that it was better than X in some other sense. Would you prefer to write production code in FORTRAN, ALGOL 60 and 68, Turbo Pascal, or Smalltalk to writing it in C today?

Yes. Though I tend to use PLT Racket these days when the choice of language is not constrained by other factors.

Re: The Unreasonable Effectiveness of C

#108

Post by coffeeaddicted »

jmaygarden wrote: post #91
AshleysBrain wrote: post #31

I always get bashed for saying I like C++, but I genuinely don't get how C programmers manage without code like this: std::map > foo; One line and you've set up a nontrivial data structure with automatic memory management. No macro horrors (which are a diabolical way of implementing what C++ templates do well). Since you can code like C in C++, I'm not sure why more people don't use C-with-templates as a programming…

Does that actually compile in C++11? I haven't used C++ in a while, but you used to need whitespace to separate the two closing angle brackets (i.e. ">>" should be "> >"). Personally, I use C for my embedded work and Python for test applications and data processing. C++ is in the middle and I haven't had a use for it.

Yes, that got changed/fixed with c++11. So you can now use >> there.

Re: The Unreasonable Effectiveness of C

#109

Post by SeanDav »

madhadron wrote: post #53

Oh for heavens' sakes. Yet more ignorance. A more realistic view of C: - C is straightforward to compile into fast machine code...on a PDP-11. Its virtual machine does not match modern architectures very well, and its explicitness about details of its machine mean FORTRAN compilers typically produce faster code. The C virtual machine does not provide an accurate model of why your code is fast on a modern machine. The…

Madhadron, you make a lot of claims but provide no detail. Also using terms like "virtual machine" with respect to C is plainly ridiculous and a case of bullshit baffles brains.

Turbo Pascal vs C? Really? In its time Turbo Pascal was an amazing piece of software but in the grand scheme of things it is a pimple compared to the whale that is C. Please compare all software written in Turbo Pascal as opposed to C if you have any doubts. The same goes for Smalltalk, Lisp, Algol 60/68. All great products/languages but very niche.

Fortran can be faster than C in some areas but again it is a niche language.

I could go on a lot more but quite frankly I don't think your post merits much more discussion and is borderline trollish.

Re: The Unreasonable Effectiveness of C

#110

Post by mbq »

AshleysBrain wrote: post #31

I always get bashed for saying I like C++, but I genuinely don't get how C programmers manage without code like this: std::map > foo; One line and you've set up a nontrivial data structure with automatic memory management. No macro horrors (which are a diabolical way of implementing what C++ templates do well). Since you can code like C in C++, I'm not sure why more people don't use C-with-templates as a programming…

I bet in 99% of cases using such structure is a nonsense overhead, and in 85% the code relaying on it can be written without a single heap allocation.
Post reply on HN