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I’m just going to start teaching classes of C programming to university first-year CS students. Would you teach `defer` straight away to manage allocated memory?
In university? No, absolutely not straight away. The point of a CS degree is to know the fundamentals of computing, not the latest best practices in programming that abstract the fundamentals.
Earlier quoted context omitted.
> still stay with C89 You're missing out on one of the best-integrated and useful features that have been added to a language as an afterthought (C99 designated initialization). Even many moden languages (e.g. Rust, Zig, C++20) don't get close when it comes to data initialization.
Just straight up huffing paint are we.
E.g. neither Rust, Zig nor C++20 can do this:
https://github.com/floooh/sokol-samples/blob/51f5a694f614253...
Odin gets really close but can't chain initializers (which is ok though):
https://github.com/floooh/sokol-odin/blob/d0c98fff9631946c11...
The article is a bit dense, but what it's announcing is effectively golang's `defer` (with extra braces) or a limited form of C++'s RAII (with much less boilerplate). Both RAII and `defer` have proven to be highly useful in real-world code. This seems like a good addition to the C language that I hope makes it into the standard.
I think that defer is actually limited in ways that are good - I don't see it introducing surprising control flow in the same way.
Earlier quoted context omitted.
>pretty reasonable It starts out small. Then before you know the language is total shit. Python is a good example. I am observing a very distinguishable phenomenon when internet makes very shallow ideas mainstream and ruin many many good things that stood the test of time. I am not saying this is one of those instances, but what the parent comment makes sense to me. You can see another comment who now wants to go fur…
I get your point, though in the specific case of defer, looks like we both agree it's really a good move. No more spaghetti of goto err_*; in complex initialization functions.
Actually I am not sure I do. It seems to me that even though `defer` is more explicit than destructors, it still falls under "spooky action at a distance" category.
A long overdue feature. Though I do wonder what the chances are that the C subset of C++ will ever add this feature. I use my own homespun "scope exit" which runs a lambda in a destructor quite a bit, but every time I use it I wish I could just "defer" instead.
I’m just going to start teaching classes of C programming to university first-year CS students. Would you teach `defer` straight away to manage allocated memory?
IMHO, it is in the best interest of your students to teach them standard C first.
Earlier quoted context omitted.
C++ destructors are implicit, while defer is explicit. You can just look at the code in front of you to see what defer is doing. With destructors, you need to know what type you have (not always easy to tell), then find its destructor, and all the destructors of its parent classes, to work out what's going to happen. Sure, if the situation arises frequently, it's nice to be able to design a type that "just works" in…
Implicitness of destructors isn't a problem, it's an advantage - it makes code shorter. Freeing resources in an explicit way creates too much boilerplate and is bug-prone. > With destructors, you need to know what type you have (not always easy to tell), then find its destructor, and all the destructors of its parent classes, to work out what's going to happen Isn't it a code quality issue? It should be clear from cl…
It's absolutely a problem. Classically, you spend most of your time reading and debugging code, not writing it. When there's an issue pertaining to RAII, it is hidden away, potentially requiring looking at many subclasses etc.
I’m just going to start teaching classes of C programming to university first-year CS students. Would you teach `defer` straight away to manage allocated memory?
If you're teaching them to write an assembler, then it may be worth teaching them C, as a fairly basic language with a straightforward/naive mapping to assembly. But for basically any other context in which you'd be teaching first-year CS students a language, C is not an ideal language to learn as a beginner. Teaching C to first-year CS students just for the heck of it is like teaching medieval alchemy to first-year…
I’m just going to start teaching classes of C programming to university first-year CS students. Would you teach `defer` straight away to manage allocated memory?
IMHO, it is in the best interest of your students to teach them standard C first.
The article is a bit dense, but what it's announcing is effectively golang's `defer` (with extra braces) or a limited form of C++'s RAII (with much less boilerplate). Both RAII and `defer` have proven to be highly useful in real-world code. This seems like a good addition to the C language that I hope makes it into the standard.
Probably closer to defer in Zig than in Go, I would imagine. Defer in Go executes when the function deferred within returns; defer in Zig executes when the scope deferred within exits.
By the way, GCC and Clang have attribute((cleanup)) (which is the same, scope-based clean-up) and have done for over a decade, and this is widely used in open source projects now.