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The Unreasonable Effectiveness of C

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Re: The Unreasonable Effectiveness of C

#131

Post by betterunix »

seiji wrote: post #12
cageface wrote: post #2

C is a fantastic high level language. Nonsense. This sudden C fad is totally baffling to me. C is a great language for low-level work and it does have an attractive minimal elegance but is in absolutely no sense of the term a high level language . A language with next to no standard containers or algorithms, manual memory management, raw pointers, a barely functional string type and minimal standard library and concu…

In traditional circles (read: not rubymongojs land), C is considered a high level language because you aren't writing assembly or maintaining stacks by hand.

You are, however, dealing with pointers, memory deallocation, the bit widths of integers, etc. C as a high level language is a questionable idea.

Re: The Unreasonable Effectiveness of C

#132

Post by cube13 »

madhadron wrote: post #104
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…

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…

>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.

Which is true, for a rather stretched definition of "virtual machine"(which falls apart at the kernel level, because it's pretty hard to work with a machine's abstraction when you're working directly on the hardware).

The problem with the virtual machine comparison is that C doesn't mask ABI access in any meaningful way. It doesn't need to, since it's directly accessing the ABI and OS. So the argument that C isn't multithreaded is rather shortsighted, because C doesn't need that functionality in the language. It's provided by the OS.

Re: The Unreasonable Effectiveness of C

#133

Post by eropple »

looser wrote: post #130
madhadron wrote: post #105

Earlier quoted context omitted.

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

If C makes use of a virtual machine, then why we have to recompile it for every new machine/platform?

Because C compilers write out to native code. It may help to think that C is the virtual machine language (as well as its specification for the virtual machine). This concept has been extended by things like Clang, that transform C to a somewhat more generic underlying language representation (LLVM bytecode) before compiling to native code.

You can ahead-of-time compile Mono code to ARM; that doesn't mean it's not defining a virtual execution environment.

Re: The Unreasonable Effectiveness of C

#134

Post by TillE »

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…

This is precisely my problem with C, and why I hate using it. Data structures are incredibly tedious.

Whenever I see younger people gushing about C, I can't help but wonder if they've actually written anything nontrivial with it. When used properly, C++ is a vastly more productive language.

Re: The Unreasonable Effectiveness of C

#135

Post by madhadron »

woodchuck64 wrote: post #114
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…

> So, before writing about the glories of C, please go familiarize yourself with modern FORTRAN, ALGOL 60 and 68, Turbo Pascal's compiler and environment, a good Smalltalk like Squeak or Pharo, and the state of modern pipelines processor architectures. All true, but how are you going to implement a single project using just the best parts of FORTRAN, ALGOL 60, Turbo Pascal and Smalltalk?

Yes, and that's the tragedy of it all...and the real reason everyone uses C. It's not that C is a well designed language appropriate for highly optimized compiling, with wonderful tooling and an elegant standard library that takes care of the difficult or insecure or repetitive tasks.

It's that I used to be able to sit down at any Unix machine in the world, shove some code into an editor, call some system libraries, get it to compile, and maybe even step through it in a debugger, and go home at the end of the day, and I could do that because that's what its designers were doing with it, so they made sure that all of it at least functioned at a good enough level to get through the day. Not always anymore, since a lot of Linux distributions no longer install the C compiler by default.

Re: The Unreasonable Effectiveness of C

#136

Post by sp4rki »

rurounijones wrote: post #34
Thrymr wrote: post #15

Earlier quoted context omitted.

> C... is in absolutely no sense of the term a high level language. Of course it is. You're not worrying about how many registers your CPU has, or when you swap a register out to memory. All that has been abstracted away for you. The fact that you can access memory locations directly gives you some low-level access, but in a very real sense C is a high-level language. There are higher-level languages with more abstra…

It may have been a high level language when it was a choice between ASM and C but the definition of "high level" has moved on. C is no longer a high level language. Just like diamonds are no longer at the top of the mohs scale. C is no longer anywhere near the top of "high" in "High level" languages.

C is and will (probably) always be a high level language by definition. That it's categorized as a lower level high level language than say Python or Ruby does not magically make it a low level language. There are low level languages which map mnemonics to instruction sets and high level languages that provide an abstraction over having to use the former and are more akin to the written word. That hasn't changed just because we have "higher level high level languages" these days.

Langauge itself is a highly variable thing. People can understand something completely different from what the originator intended, but it doesn't change what said originator meant by it. People can always say "oh C is not a high level language because I think that a low level language should be X and Y" the same way they can say "oh men have to have a beard and know how to fight to be be real men", but in reality men - beards or not - are still fundamentally men.

Re: The Unreasonable Effectiveness of C

#137

Post by bcbrown »

peterevans wrote: post #69
ryeguy wrote: post #33

Earlier quoted context omitted.

The problem is that the "level" of a language is relative to other languages. If C is a high level language, that means you can group it into the same pool as Java, C#, Haskell, Python, and Ruby. Don't you see a bit of a difference here? Unless there is a significant number of actual languages , not concepts , that are below C, it logically has to be called a "low level language" because there really isn't much below…

Here's the thing: "high-level", when applied to a programming language, has a historical context. It means something specific (see: http://en.wikipedia.org/wiki/High-level_programming_language ), and what it means and has always meant is that the language in question abstracts away registers and allows structured programming (as in, through the use of if, while, switch, for, as opposed to using labels and branching).…

Did you read the "Relative Meaning" section of that link? It specifically discusses C.

Re: The Unreasonable Effectiveness of C

#138

Post by gsg »

SeanDav wrote: post #109
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…

Seems to me that the GP was referring to the C abstract machine but used a similar, more common phrase by mistake.

Granting that, I can't say I agree with his point: C has probably ran on more machines than any other language. As an abstraction over machines it is, if not perfect, clearly good enough.

Re: The Unreasonable Effectiveness of C

#139

Post by pcwalton »

sramsay wrote: post #63

I feel like I'm always trying to make this point to people, and doing so with far less eloquence. The fact that Katz is (a) an experienced and accomplished developer and (b) someone with very non-trivial experience with hot, hip, super-high-level languages should not go unnoticed. He's not some cranky old embedded systems programmer; he's doing thoroughly modern development. Someone the other day said that the great…

What do you feel is too complex about Rust?

The region system is obviously a source of complexity. But I feel as though sacrificing safety at compile time in the name of simplicity just leads to complexity later—you either pay the complexity tax at compile time, or you transfer the complexity of correct memory management to runtime, resulting in sessions sitting in front of gdb or valgrind.

Re: The Unreasonable Effectiveness of C

#140

Post by MichaelSalib »

SeanDav wrote: post #109
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…

Also using terms like "virtual machine" with respect to C is plainly ridiculous and a case of bullshit baffles brains.

Note that the C language standards are written in terms of an "abstract machine". For example, "When the processing of the abstract machine is interrupted by receipt of a signal, only the values of objects as of the previous sequence point may be relied on" from 5.1.2.3.

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