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Modern C [pdf]

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Re: Modern C [pdf]

#271

Post by clarry »

sqeaky wrote: post #270
clarry wrote: post #265

Earlier quoted context omitted.

I don't think anyone can demonstrate that it is virtually impossible to write 100% safe C code. Sure, you can always find people who don't know how to write a proper safety check. That doesn't mean nobody knows. You can always find people who ignore or don't know about best practices, but that doesn't mean everyone's like them. And you can find people who write goto fail; and ignore the warnings about unreachable cod…

I think that you have the formulation backwards. You claim that people can just write better, and should attain perfection. > I don't think anyone can demonstrate that it is virtually impossible to write 100% safe C code. I think most people come at the other way. Most people are aware that they are fallible and wants tools to help with that. Most people strive for perfection and none will ever actually attain it. >…

> which then results in every caller ignoring the return value

And a whole load of compiler warnings. Worse yet, people who ignore warnings might ignore them.

> Now imagine the advances in error detection moving to languages that catch additional classes of errors.

Languages don't catch errors, tools do. The C tooling has been and still is constantly improving.

Re: Modern C [pdf]

#272

Post by FloDo »

yoha wrote: post #187
colanderman wrote: post #156

While I like a lot of what's in here, for (size_t i = 9; i is a pretty terrible example to put in the second chapter. I would not let that line pass code review. There is no need or place for cutesy cleverness in C. EDIT: Ugh, just found this too: isset[!!largeA[i]] += 1; Not only is that confusingly cutesy, but largeA[i] is a double . Please DON'T write – or encourage beginners to write! – such smug code! EDIT2: In…

Decrementing loops is the one place where I have indulged in some trickery. I do: for (size_t i = 9; i --> 0; ) This has the advantage to be very easy to pattern-match once known. Obviously, for a beginner, I would just do: for (int i = 9; i >= 0; i -= 1)

Do you even realize that these two loops are not equivalent? One of them starts at 8, then other one starts at 9 ...

Re: Modern C [pdf]

#273

Post by duneroadrunner »

paulmd wrote: post #237
yekim wrote: post #225

Earlier quoted context omitted.

Hear, hear! Unfortunately, C does get a lot of hate on HN. I suspect it has to do with this site's demographics. Many (not all) of the HN clan seem to be oriented towards / mostly familiar with web based technologies. I suspect that for many who have tried, going from a web dev environment to a C oriented dev environment feels like a robust shock to the system. I'd also be willing to bet that there's an age bias at p…

It's not just that HN does a lot of webdev. It's that even in its element as a "systems language" it's virtually impossible to write 100% safe C/C++ code and guarantee that it will remain safe into the future, even for experts who are making every effort to do it right. There are just too many gotchas with "undefined behavior" and too many clever compilers out there waiting for you to make a mistake. One only needs t…

> Yes, it's fast, but at what cost? I would gladly give up a massive fraction of my performance for better security and portability - and that's why I program Java.

While I agree with the sentiment, a problem with Java is that you're dependent on a runtime environment with a fairly consistent history of vulnerabilities, right? [0][1]

> Personal opinion here, but with few exceptions C/C++ are inappropriate languages for starting new development at this point.

Maybe, but now there's SaferCPlusPlus [2]. At least it may be a practical option for improving memory safety in many existing code bases.

[0] http://www.cvedetails.com/product/19117/Oracle-JRE.html?vend...

[1] http://www.cvedetails.com/product/1526/SUN-JRE.html?vendor_i...

[2] shameless plug: https://github.com/duneroadrunner/SaferCPlusPlus

Re: Modern C [pdf]

#274

Post by dvirsky »

PDoyle wrote: post #44
mixedCase wrote: post #42

Earlier quoted context omitted.

>The omission of assert() makes Go a non-starter. A small syntactic sugar you can trivially implement yourself makes Go a non-starter? Go doesn't include assert in the language because you're supposed to do better than assert. Assert easily allows lazy programmers to let their programs freely crash without properly handling error conditions. Go prevents you from compiling with unused variables, and that combined with…

> Assert easily allows lazy programmers to let their programs freely crash without properly handling error conditions. This is what he meant by misuse. Properly-used assertions are meant to document and check conditions that were thought to be impossible by the developer. Not just unlikely, or illegal, but impossible. If a condition is possible, and you check it with assert, that's a bug.

I came to detest assert when I was working on a project with another guy, who used it generously, as a substitute for assertions in (non existing) unit tests. Nothing would annoy me more than working on my code, running it, and having all sorts of weird assertions pop up all over the place from this guy's code.

Re: Modern C [pdf]

#275

Post by AsyncAwait »

xenihn wrote: post #232
jackhack wrote: post #179

I wish I could like this book, but after reviewing the first chapter I can only imagine the confusion of students. I support very much the idea of breaking the book into levels, but it attempts to cover far too much, far too quickly and I don't believe this book would be useful for those who are not already familiar with the language. I've been writing C since the late 1980s, moved to mostly C++ by the mid 90s, C# in…

Do you have any recommendations for books?

I cannot recommend "C Programming: A Modern Approach" [1] enough.

[1] - https://www.amazon.com/C-Programming-Modern-Approach-2nd/dp/...

Re: Modern C [pdf]

#276

Post by khedoros1 »

jimbokun wrote: post #264
fryguy wrote: post #249

Earlier quoted context omitted.

> "what does `public static void main` mean?" The problem with this question is that there is a ton of stuff you need to understand before you can really answer that question fully. To know what public means, you need to understand classes, and visibility rules for classes. To understand static fully, you kind of need to know how c++ works, since it's equivalent to a bare function in a namespace. Void is the type of…

"The problem with this question is that there is a ton of stuff you need to understand before you can really answer that question fully." Which is why Java is a terrible language for an introductory programming class.

It was the first object-oriented language that I learned, and some of my classmates' first language. It wasn't too bad to be told "Just type it for now; we'll get into object orientation next week and explain it then." From my own experience, I don't think it's a big issue if it's introduced correctly.

Re: Modern C [pdf]

#277

Post by dvirsky »

solidsnack9000 wrote: post #25
SwellJoe wrote: post #9

It's been a decade or more since I've worked in C (and have never been a heavy C coder). Is "modern C" really a thing? I mean, is there some subset of C that is safer than what I think of when I think of C? I know about stuff like reference counting techniques, rather than manual memory management, for example, and that goes miles towards safer coding. But, even so, the variety of ways you can shoot yourself in the f…

> Would anyone choose C for a new systems project with no legacy baggage or dependencies, in a world with Rust and Go? While Rust might be feasible, Go can't really provide libraries like SQLite: Go's C compatibility story is disappointing and awkward.

Having written a project that loads Go plugins to a C app (namely redis), it's not great but in recent Go versions it's not too bad as well.

Re: Modern C [pdf]

#278

Post by sqeaky »

FrancoDiaz wrote: post #208
chrisd1100 wrote: post #114

I'm really surprised by the "hate" for C that is appearing in these comments. What ever happened to actually enjoying the danger of getting low level? Is assembly also useless because it isn't readable? There is a lot of great code written in C, and a lot of crappy code written in C. Because C doesn't protect you from yourself, it exacerbates any design flaws your code may have, and makes logical errors ever more ins…

I don't hate C. I'd rather program in C than C++. There's a "uniformity" and simplicity about C that makes it beautiful. You've got structs, functions, and pointers...that's it. I remember reading some of ID's engine code and admiring how well I could follow it and know what's going on. With C++ and other OO languages, it's much harder. Don't get me wrong, I'm not going to write my next web app in C, and there's some…

Comments like this perplex me. I am a full time C++ dev and I could just rewrite your comment woving the "++" to the other "C".

Really like that I can create a class that stores all the knowledge of one concept internally and if I wrote that correctly I never need to look inside it again. Even better, if I document the contracts of using a class I can carefully optimize it and have broad performance effects with small code changes.

Things like std::string are just so much easier to work with that their C counterpart and things like std::filesystem::path simplify (or use the boost one if you don't have C++17 yet) so many things and doesn't even have a C counterpart. I point these out as simple examples but in all the code bases I have worked on there are similar examples, like most games a class to represent 2d and 3d points, which are used to define AxisAlignedBoundingBoxes, which are needed for collision detection algorithms which them selves need several classes to describe.

Then I can build systems of a size and complexity I literally could not comprehend without those abstractions. And then the compiler enforces them for me so other people can use them safely as well. Why is it so much harder to do this in C if C is so much "simpler".

Re: Modern C [pdf]

#279

Post by ticviking »

Longhanks wrote: post #262
fryguy wrote: post #249

Earlier quoted context omitted.

> "what does `public static void main` mean?" The problem with this question is that there is a ton of stuff you need to understand before you can really answer that question fully. To know what public means, you need to understand classes, and visibility rules for classes. To understand static fully, you kind of need to know how c++ works, since it's equivalent to a bare function in a namespace. Void is the type of…

Then why start teaching programming with Java in the first place when understanding those concepts involves an at least mediocre understanding of object orientation? There are many more languages that implement a "Hello, world!" with one line of code. If explaining "public static void main" is too hard, maybe one is using the wrong tool.

This is an idea that many people resist. I think they mistakenly believe that programming languages are genuinely difficult to learn, and students must start on one that is marketable.

Re: Modern C [pdf]

#280

Post by ticviking »

khedoros1 wrote: post #276
jimbokun wrote: post #264

Earlier quoted context omitted.

"The problem with this question is that there is a ton of stuff you need to understand before you can really answer that question fully." Which is why Java is a terrible language for an introductory programming class.

It was the first object-oriented language that I learned, and some of my classmates' first language. It wasn't too bad to be told "Just type it for now; we'll get into object orientation next week and explain it then." From my own experience, I don't think it's a big issue if it's introduced correctly.

I suspect you are far more willing to learn by rote than some other students.

For a particular kind of curious student, "just do it because you have to" is a very fast way to them checking out and doing nothing at all.

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