This is a weird (to me) way of presenting Zig syntax and operation. I would generally assume that someone coming to Zig would be familiar with C/C++ or Rust and only need to be able to map Zig syntax to things they already know.
If the author's content is all in this 'assume no C background' style, it will be useful to those without previous manual memory management background in contrast to most articles that assume a lot of context.
In C you can use `[0]` as a postfix dereferencing operation... ugly but it works. I use it a lot in GDB. But I agree that Pascal does it better here, the dereferencing operator should have been postfix all along.
The thing I really wish C had, and which there is no straightforward workaround for, is postfix casting. When you do `((struct foo*)(COMPLEX_EXPRESSION))->field`, I think it would read a lot better if the `(struct foo*)` cast was on the same side as `->field`. Maybe something like `(COMPLEX_EXPRESSION)@(struct foo*)->field`
`->` shouldn't be necessary to begin with... if the LHS is a pointer already, `.` could just auto-dereference it instead of generating an error like it does now.
Note that when you define smart pointer types C++ there is indeed a difference between `.` and `*` resp. `->`: the latter are typically overloaded to operate on the underlying pointer type whereas the former operates on the smart pointer class itself (e.g. calling `reset` on a `std::unique_ptr`). Not sure how you would do that with a single dereference operator.
I always wondered about that. Is there some technical reason that it was designed the way it was? Is it disambiguating something?
It seems like `.` could in theory be made to recursively dereference any number of layers down to the base type. It's not as though `.` has any other possible meaning when used directly against an address ... right?
Historical reasons: early C compilers didn't actually keep track of what the type of the LHS was, so they needed `.` vs `->` to properly disambiguate. Later C compilers did start tracking that, so the difference in syntax was no longer necessary, but stuck for reasons of history and backward compatibility
In Pascal, it's a distinct operator from field access, though.
What this actually reminds me of is Ada, where you write `value.all` to basically the same effect as Zig's `value.*`. It's as if everything is a struct with itself as a member.
Didn't know anything about Zig, but the .* syntax alone was straight-forward and easy to understand, as is regular copying from one existing memory location to another.
I think what seems weird though is more the "... = .{...}" syntax.
This makes it look as if there was some kind of anonymous object ".{...}" in memory that you're copying from, but there isn't. It's actually just a writing operation and the .{...} itself doesn't represent anything.
Maybe that was also what the author found confusing?
Yeah I found this article super weird. Explaining pointers & dereferencing is reasonable, but doing it in the context of Zig specifically, like Zig is the first language to feature dereferencing, is odd. Especially since pointers are such a fundamental part of low-level (really, any) programming. Also not sure why it's posted here?
Edit: Going through this author's website, it seems like a lot of their posts are about rediscovering low-level programming concepts through Zig. Like this article, where they discover you can't compare strings directly, and you have to use memcmp:
They claim that they blog because they "find that [they] retain things better when I write about them." No problem with that. Just a little odd to see on the hn front page, I suppose.
I think this is just "discovering". While you (and I) probably discovered these things with assembly or C languages, it's perfectly reasonable or even appropriate for newer generations to have these kinds of experiences with Zig or Rust.
I don't think people understand how abstracted most modern developers in today's world are.
If learning Piano was an example then everyone would have like you said learn the basic of everything and then build up on it. Modern day people learn multiple different chords and somehow string them together. If you do EE you have have learned how the piano works before you start playing the piano.
Worth remembering most people in programming today start with Javascript / Python or Ruby.
Absolutely, like I said, there's no problem with what this person is doing or the way that they're exploring computers, I'm just confused as to why it's being posted here.
Author here. I agree this is a less-than captivating piece. I write a lot about Zig and wanted something I could reference from other pieces.
But, to answer your question directly: absolutely. In addition to writing a lot about it, I maintain some popular libraries and lurk in various communities. Let me assure you, beginner memory-related questions come up _all the time_. I'd break them down into three groups:
1 - Young developers who might have a bit of experience in JavaScript or python. Not sure how they're finding their way to Zig. Maybe from HN, maybe to do game development. I think some come to Zig specifically to learn this kind of stuff (I've always believed most programmers should know C. Learning Zig gets you the same fundamentals, and has a lot of QoL stuff).
2 - Hobbyist. Often python developers, often doing embedded stuff. Might be looking to write extensions in Zig (versus having to do it in C).
3 - Old programmers who have been using higher level languages for _decades_ and need a refresher. Hey, that's me!
Also, from learning human languages, it's a well-known lesson that phrasebook-type "this means this" translations (like some here are asking, from Zig to C/Rust) are useful for quick and dirty learning good enough for one trip, but long term learning needs this kind of a direct explanation.
1. It avoids the word (or syntax in this case) getting stuck in a double-indirection state, needing you to mentally translate it from Zig to C to what it actually means every time.
2. It avoids the learner attaching the wrong nuances to the word or syntax feature, based on the translation they're given, when the language they're learning has different nuances. In other words, it helps the learner see it as its own thing, and not be unduly colored by what they already know and find easy to grasp on to (even when it's subtly wrong).
The author may not know C. As OP said, it's definitely the case that people interested in Zig may not have any interest in going through C first. They may eventually have to, as Zig interfaces heavily with C code and libs, but there's nothing wrong with going Zig first.
It feels a bit performative to me: the article goes out of way not to explain it by giving the C equivalent.
Perhaps some day Zig will have replaced C and beginners will come to Zig having never touched C, and in that context this approach makes sense - after all, you wouldn't litter an introductory article on C with comparisons to Algol. But today, surely the modal Zig beginner already knows enough C that the syntax would better be explained by reference to C.
And why change something like that? The world would be a better place, IMHO, if there were less different ways to write something from language to language.
Sometimes it seems like the change is just to make it different, not better.
I think Rust could use some syntax improvements for pointer manipulation. It has suffix .await, so maybe the community is ready for suffix .* for dereference now too. Visually scanning left and right, along with the extra parentheses, makes pointer-based code in Rust worse than C++ almost. A fully left-to-right syntax would be amazing. EDIT: found https://github.com/rust-lang/rust/issues/10011 and https://github.com/rust-lang/rfcs/pull/3577
I’ve gotta say, when I first learned Rust had gone its own way on await, I was heavily sceptical. But seeing the actual examples was pretty compelling.
The fact that the author of Zig who's extremely well versed in C and C++ went this way should make you at least try to think why he went that way before dismissing it.
It's remarkably intuitive and sensible if you remember that . in Zig auto-dereferences for field access and then treat `*` in this construct as field name denoting the entire object.
Ada does the same exact thing, except there you write `p.all` instead.
In any case, while the exact syntax may not be ideal, using a postfix operator for dereferencing is vastly better than prefix in practice due to typical patterns of use. There's a reason why you end up writing () a lot in C code with heavy pointer operations - the things they end up mixed with most often turn out to have the wrong kind of priority and/or precedence more often than not. Things are much simpler when everything is postfix and code reads naturally left-to-right.
(I'd suggest the latter is now the more readable of the two).
Where there is a VFT in each of the xxx_out structures, and the calls simply returns the VFT, while the whole abstraction is stored/returned via the out arguments.
In general, the rule of thumb is that prefix and postfix operators don't mix well in a single expression - order of operations is confusing, and reading the code requires going back and forth to follow it.
In the ideal world, we wouldn't have unary prefix operators at all, but unfortunately unary +, -, and NOT are prefix mostly because they were that in math notation and got grandfathered in (bonus points to Smalltalk here for going with consistency here - "not" and "negated" are regular nullary methods there so it's postfix throughout!). However, these are rarely themselves an operand of another unary operator, so you can mostly deal with this by giving postfix higher precedence than prefix in all cases, so at least it's a simple rule. But then for pointer dereference, it is in fact common to have the result of a dereference itself be an operand in the middle of another expression.
So now you have some choices to make. If you make the pointer dereference prefix, then you don't need extra parentheses when applying other prefix operators to it, e.g. -*p or !*p. If you make it postfix, then you don't need extra parentheses when applying other postfix operators to it, e.g. (using Pascal-style ^ for dereferencing) p^[0] or p^.x. Alternatively, you could add special postfix operators that desugar into the combination but avoid those extra parens, which is what C did with -> for field access.
(Technically, you could also make everything prefix instead, e.g. field access ALGOL 68 style: `month OF birthDate OF person`. But this is very counter-intuitive with indexing, and also makes code completion unusable, so it's not a serious option.)
You will know because any text editor or IDE worth the name will light up that ".await" in such a way you will immediately know it's not a method call or a struct field. The entire construct, including the dot, is a postfix keyword.
This syntax is less arbitrary than C's. It draws a syntactic parallel between accessing a single member and accessing "all members". (by using pattern-matching-like syntax)
It makes the language more consistent and one's mental model of it smaller. (Even though I doubt that patterns other than the Kleene star would work)
Yes, but unlike C's terribly confusing "declaration follows usage" style, which no tells you about btw, zig's pointer syntax doesn’t turn into a nightmarish puzzle.
In Zig, you can pretty much read the types aloud and it makes, your brain does not need to peek for parsing.
For me it's too late, I got used to the C way but I still want the better thing to get adopted.
No more int ((foo)(int))[5]; nonsense—just T, [N]T, or *T, making intent crystal clear.
Yeah, not sure where that came from. The ANSI C standard was extensively documented in books and articles and specs at all levels of rigor starting from the mid-80's. No one has ever lacked for a reference for how function pointer declaration looks.
That said, C's function pointer declaration syntax is indeed awful. But really that's because ANSI took a very hardline "no incompatible changes" tact when adding prototypes to the language, which limited the ways they could express them. That decision is one of the reasons we're still writing C today. Any yahoo can come up with a new language, kids do it all the time. ANSI's job was to add features to the language in which Unix was already written.
Hey I started using Zig after a decade of JS/Elm/Haskell/php/scala, such articles are very useful to me. Haven't used lower lever languages in a long time.
Makes sense, it seems like you missed languages with pointers.
I would suggest going through C. Otherwise it's like learning C++ without learning C. Zig is similarly a successor to C, (it is phonetically named after it).
That would address your blind spots and let you appreciate Zig's identity
Learn C so you can avoid beginner content on Zig /s.
You're making many wrong assumptions at the same time:
- that I've never used C or C++ (both wrong)
- that I don't know pointers (also wrong, nor it is a particularly difficult topic)
- that you need to go through C again to learn Zig. Have you met many people that picked up Zig as their first programming (or first system programming) language to make those statements?
Because I am in both the IRC and discord and there's plenty of people that get proficient in Zig starting from it.
I don't understand the snark. Is it not possible to write articles for beginners? There are also a lot of developers who have never dealt with memory allocation and are interested in Zig.
Yes it is possible to write articles for begginners, but they should be on begginner concepts.
Writing about an advanced concept catering to begginners is a mess. It's like writing about logarithmic calculus and prefacing with an explanation on exponents.
However, thinking long term, are we going to continue to introduce pointers via C to new students? If not, then how? C++ or Zig seem viable options, so this might be a long term proposition.
I definitely remember casting pointers to ints and printing them to prove to myself what it was pointing to and what the offset was for the next value e.g. in an array.
In C you can also do those fun array indexing and pointer arithmetic tricks that require you truly understand the concept of "address plus offset" that basically everything uses.
But even if that's a hallucination, Rust does the hard work of keeping pointers off your mind by a combo of refs, box, etc. and Rust is not a good first language, I don't think, for a variety of reasons.
My ultimate programing curriculum if I had to make one would teach you to program in python, then show you C via Cython or similar. Lots of allocation and free under the hood in Python.
Casting pointers to ints is generally safe (at least as long as you use intptr_t instead of assuming that the size of pointers will never change).
The issue comes when you try casting to pointers. Because of providence, aliasing rules, and a couple of dragons that built a nest in the C language specification, you could have two pointers to the exact same memory locations, but have the program be undefined if you use the wrong pointer.
Granted, this doesn't stop you from doing things like
foo_t *foo = (foo_t*) 0xDEADBEEF
And in the few occasions where that is something you would reasonably want to do it does more or less what you would expect (unless you forgot that the CPU sticks a transparent cache between you and the memory bus; but not even assembly would save you from that oversight).
Provenance (outside programming this is the distinction between "I reckon this old table is a few hundred years old" and "Here is the bill of sale from when my grandfathers ancestors had the table made from the old tree where that cherry tree is now in 1620") not Providence.
In Rust pointer provenance is a well defined language feature and if you go to the language docs you can read how it interacts with your use of raw pointers and the twin APIs provided for this.
In C the main ISO document just says basically here be dragons. There's an additional TS from 2023 with better explanation, but of course your C compiler even if it implemented all of C23 needn't necessarily implement that TS. Also of course the API is naturally nowhere near as rich as Rust's. C is not a language where pointers have an "addr" method so they also don't need a separate exposure API.
I suspect that in Zig none of this is clearly specified.
This is a weird (to me) way of presenting Zig syntax and operation. I would generally assume that someone coming to Zig would be familiar with C/C++ or Rust and only need to be able to map Zig syntax to things they already know.
If the author's content is all in this 'assume no C background' style, it will be useful to those without previous manual memory management background in contrast to most articles that assume a lot of context.
This is the way that Pascal does it, which was always more sensible than prefix notation. Pascal uses ^
In C you can use `[0]` as a postfix dereferencing operation... ugly but it works. I use it a lot in GDB. But I agree that Pascal does it better here, the dereferencing operator should have been postfix all along.
The thing I really wish C had, and which there is no straightforward workaround for, is postfix casting. When you do `((struct foo*)(COMPLEX_EXPRESSION))->field`, I think it would read a lot better if the `(struct foo*)` cast was on the same side as `->field`. Maybe something like `(COMPLEX_EXPRESSION)@(struct foo*)->field`
That is very nice. If you treat the star as a postfix operator, then even "->" is no longer needed:
`->` shouldn't be necessary to begin with... if the LHS is a pointer already, `.` could just auto-dereference it instead of generating an error like it does now.
Note that when you define smart pointer types C++ there is indeed a difference between `.` and `*` resp. `->`: the latter are typically overloaded to operate on the underlying pointer type whereas the former operates on the smart pointer class itself (e.g. calling `reset` on a `std::unique_ptr`). Not sure how you would do that with a single dereference operator.
I always wondered about that. Is there some technical reason that it was designed the way it was? Is it disambiguating something?
It seems like `.` could in theory be made to recursively dereference any number of layers down to the base type. It's not as though `.` has any other possible meaning when used directly against an address ... right?
Historical reasons: early C compilers didn't actually keep track of what the type of the LHS was, so they needed `.` vs `->` to properly disambiguate. Later C compilers did start tracking that, so the difference in syntax was no longer necessary, but stuck for reasons of history and backward compatibility
https://retrocomputing.stackexchange.com/questions/10812/why...
In a way, Zig is Modula-2 with curly brackets for folks with C background.
Yes, I know, comptime and such.
In Pascal, it's a distinct operator from field access, though.
What this actually reminds me of is Ada, where you write `value.all` to basically the same effect as Zig's `value.*`. It's as if everything is a struct with itself as a member.
Didn't know anything about Zig, but the .* syntax alone was straight-forward and easy to understand, as is regular copying from one existing memory location to another.
I think what seems weird though is more the "... = .{...}" syntax.
This makes it look as if there was some kind of anonymous object ".{...}" in memory that you're copying from, but there isn't. It's actually just a writing operation and the .{...} itself doesn't represent anything.
Maybe that was also what the author found confusing?
Nice explanation of zig's dereferencing operator. Thanks!
Article says it’s about stack addresses but I think it should apply more generally to dynamically allocated memory as well.
Tl;dr: It is just pointer dereferencing.
I.e. C's
is in Zig.Yeah I found this article super weird. Explaining pointers & dereferencing is reasonable, but doing it in the context of Zig specifically, like Zig is the first language to feature dereferencing, is odd. Especially since pointers are such a fundamental part of low-level (really, any) programming. Also not sure why it's posted here?
Edit: Going through this author's website, it seems like a lot of their posts are about rediscovering low-level programming concepts through Zig. Like this article, where they discover you can't compare strings directly, and you have to use memcmp:
https://www.openmymind.net/Switching-On-Strings-In-Zig/
They claim that they blog because they "find that [they] retain things better when I write about them." No problem with that. Just a little odd to see on the hn front page, I suppose.
> rediscovering
I think this is just "discovering". While you (and I) probably discovered these things with assembly or C languages, it's perfectly reasonable or even appropriate for newer generations to have these kinds of experiences with Zig or Rust.
Is it?
When learning piano you first learn how to play rudiments and then you move up to more complex scores.
Otherwise you end up writing an article about how Ravel' Scarbo is amazing because it involves playing with two hands at the same time.
https://youtu.be/2BT7_owW2sU?si=VNpy3K6UXSkAsn7u
I don't think people understand how abstracted most modern developers in today's world are.
If learning Piano was an example then everyone would have like you said learn the basic of everything and then build up on it. Modern day people learn multiple different chords and somehow string them together. If you do EE you have have learned how the piano works before you start playing the piano.
Worth remembering most people in programming today start with Javascript / Python or Ruby.
There's amateur and outsider musicians for sure, I've seen them. They learn by hearing, usually listen to pop or rock, not classically trained.
More common with guitar than piano though.
Similarly they are most popular with Javascript than with C
not when you can let an ai play the notes for you
Absolutely, like I said, there's no problem with what this person is doing or the way that they're exploring computers, I'm just confused as to why it's being posted here.
Maybe the place is not reserved to old grey beard? :)
Rediscovering is a perfectly fine word for one person discovering for the first time what others have discovered before.
Yeah, I kept on reading to find out if there is some Zig-specific twist but it is literally just that.
Are there really that many Zig programmers that have never seen C or know what pointers are?
Author here. I agree this is a less-than captivating piece. I write a lot about Zig and wanted something I could reference from other pieces.
But, to answer your question directly: absolutely. In addition to writing a lot about it, I maintain some popular libraries and lurk in various communities. Let me assure you, beginner memory-related questions come up _all the time_. I'd break them down into three groups:
1 - Young developers who might have a bit of experience in JavaScript or python. Not sure how they're finding their way to Zig. Maybe from HN, maybe to do game development. I think some come to Zig specifically to learn this kind of stuff (I've always believed most programmers should know C. Learning Zig gets you the same fundamentals, and has a lot of QoL stuff).
2 - Hobbyist. Often python developers, often doing embedded stuff. Might be looking to write extensions in Zig (versus having to do it in C).
3 - Old programmers who have been using higher level languages for _decades_ and need a refresher. Hey, that's me!
Hey, that's me too!
Also, from learning human languages, it's a well-known lesson that phrasebook-type "this means this" translations (like some here are asking, from Zig to C/Rust) are useful for quick and dirty learning good enough for one trip, but long term learning needs this kind of a direct explanation.
1. It avoids the word (or syntax in this case) getting stuck in a double-indirection state, needing you to mentally translate it from Zig to C to what it actually means every time.
2. It avoids the learner attaching the wrong nuances to the word or syntax feature, based on the translation they're given, when the language they're learning has different nuances. In other words, it helps the learner see it as its own thing, and not be unduly colored by what they already know and find easy to grasp on to (even when it's subtly wrong).
> Not sure how they're finding their way to Zig.
Lots of popular Youtubers such as Primeagen (somebody who easily gets 200/300k+ views per video) have been speaking highly about Zig.
Perhaps add a brief paragraph, for C folks, that draws parallels between the Zig code and C. You never know, other readers may find it useful as well.
The author may not know C. As OP said, it's definitely the case that people interested in Zig may not have any interest in going through C first. They may eventually have to, as Zig interfaces heavily with C code and libs, but there's nothing wrong with going Zig first.
It feels a bit performative to me: the article goes out of way not to explain it by giving the C equivalent.
Perhaps some day Zig will have replaced C and beginners will come to Zig having never touched C, and in that context this approach makes sense - after all, you wouldn't litter an introductory article on C with comparisons to Algol. But today, surely the modal Zig beginner already knows enough C that the syntax would better be explained by reference to C.
I know some C but I haven't touched it in a decade, but I have started playing with Zig so this was useful to me.
You aren't always the target.
And why change something like that? The world would be a better place, IMHO, if there were less different ways to write something from language to language.
Sometimes it seems like the change is just to make it different, not better.
Same reason Rust uses foo.await instead of await foo. It's clearly superior syntax.
The whole point of Zig is to fix C's mistakes. I don't know why they'd repeat this one.
I think Rust could use some syntax improvements for pointer manipulation. It has suffix .await, so maybe the community is ready for suffix .* for dereference now too. Visually scanning left and right, along with the extra parentheses, makes pointer-based code in Rust worse than C++ almost. A fully left-to-right syntax would be amazing. EDIT: found https://github.com/rust-lang/rust/issues/10011 and https://github.com/rust-lang/rfcs/pull/3577
I’ve gotta say, when I first learned Rust had gone its own way on await, I was heavily sceptical. But seeing the actual examples was pretty compelling.
At this point &var and *var are pretty much an established way across languages, like if-else. I don’t see any benefit of reinventing this paradigm.
You mean like if-else if, if-elseif, if-elsif, if-elif? I think I should use eif for my next language. You can have elsf and elf.
It’s not that important though. Many people write two or more languages without mixing the syntax.
p.* and lv.& would be good post-operators, imo. Less going left and parenthesizing.
The fact that the author of Zig who's extremely well versed in C and C++ went this way should make you at least try to think why he went that way before dismissing it.
Agreed. And p.* is remarkably unintuitive and nonsensical compared to *p.
It's remarkably intuitive and sensible if you remember that . in Zig auto-dereferences for field access and then treat `*` in this construct as field name denoting the entire object.
Ada does the same exact thing, except there you write `p.all` instead.
In any case, while the exact syntax may not be ideal, using a postfix operator for dereferencing is vastly better than prefix in practice due to typical patterns of use. There's a reason why you end up writing () a lot in C code with heavy pointer operations - the things they end up mixed with most often turn out to have the wrong kind of priority and/or precedence more often than not. Things are much simpler when everything is postfix and code reads naturally left-to-right.
> Copying bad design is not good design.
—Andreas Rumpf
Postfix is only superior when you have lots of things to chain. C doesn't have any chaining at all. f(g(x)) is just as good as f(g(x))
One is able to chain calls in C via:
At least one person at Bell Labs historically used that scheme for some graphics program.All it requires is that the function returns a pointer to a struct which itself contains function pointers.
C also allows the dot form if you really want it:
Simply by returning structs, and for all compilers that I know if, such end up using a hidden pointers to structs.Now to make it a bit more usable, one needs a bit of planning so that either of these can be done:
(I'd suggest the latter is now the more readable of the two).Where there is a VFT in each of the xxx_out structures, and the calls simply returns the VFT, while the whole abstraction is stored/returned via the out arguments.
Gotta escape those asterisks so you don't output italics.
f(*g(*x)) is just as good as f(g(x*)*)
Hmm, function names go before parentheses, that looks like a good reason for dereferencing to be prefix too, otherwise they end up a long way apart.
But in the back of mind I'm thinking "semantics cause pointless fussy arguments, all code is ugly, let's stop programming in text somehow".
Oh yeah, forgot HN supported some markdown.
But this is literally not semantics. Semantics is everything of value, this is just syntax.
Sorry, yes, syntax. I was equating it to "purely semantic argument", arguing about the meaning of words. Here about it's where to put symbols.
why is foo.await better?
is it a method call? is it a property/field value? how am i to be indicated that there is an implicit suspend point when you .await?
It's the difference between (await (await foo).bar).baz and foo.await.bar.await.baz -- which do you want to write?
In general, the rule of thumb is that prefix and postfix operators don't mix well in a single expression - order of operations is confusing, and reading the code requires going back and forth to follow it.
In the ideal world, we wouldn't have unary prefix operators at all, but unfortunately unary +, -, and NOT are prefix mostly because they were that in math notation and got grandfathered in (bonus points to Smalltalk here for going with consistency here - "not" and "negated" are regular nullary methods there so it's postfix throughout!). However, these are rarely themselves an operand of another unary operator, so you can mostly deal with this by giving postfix higher precedence than prefix in all cases, so at least it's a simple rule. But then for pointer dereference, it is in fact common to have the result of a dereference itself be an operand in the middle of another expression.
So now you have some choices to make. If you make the pointer dereference prefix, then you don't need extra parentheses when applying other prefix operators to it, e.g. -*p or !*p. If you make it postfix, then you don't need extra parentheses when applying other postfix operators to it, e.g. (using Pascal-style ^ for dereferencing) p^[0] or p^.x. Alternatively, you could add special postfix operators that desugar into the combination but avoid those extra parens, which is what C did with -> for field access.
(Technically, you could also make everything prefix instead, e.g. field access ALGOL 68 style: `month OF birthDate OF person`. But this is very counter-intuitive with indexing, and also makes code completion unusable, so it's not a serious option.)
Is this something you write often in Rust? A promise returning a struct with a promise returning a struct with a promise.
Although I agree that await could use some precedence like new in javascript:
I’d rather parenthesize what I’m awaiting in complex cases than awaiting just everything that follows.It preserves a left to right reading of the code. You don't have to jump visually elsewhere.
You will know because any text editor or IDE worth the name will light up that ".await" in such a way you will immediately know it's not a method call or a struct field. The entire construct, including the dot, is a postfix keyword.
oh no. this is DEFINITELY a place where zig made a GOOD change away from c.
when a value is dereferenced, having a consistent left to right dereferencing makes sense.
for example, in c, without looking up the order of operations how confident are you that you know what is going on in the following:
foo = **bar[10]
If prefix * bugs you, C has a suffix deference operator as well, `[0]`.
(Yes, C programmers will probably hunt you down if you do this, but it does work.)
It's not just different.
This syntax is less arbitrary than C's. It draws a syntactic parallel between accessing a single member and accessing "all members". (by using pattern-matching-like syntax)
It makes the language more consistent and one's mental model of it smaller. (Even though I doubt that patterns other than the Kleene star would work)
A parallel with files:
In Zig you can In C:Yes, but unlike C's terribly confusing "declaration follows usage" style, which no tells you about btw, zig's pointer syntax doesn’t turn into a nightmarish puzzle.
In Zig, you can pretty much read the types aloud and it makes, your brain does not need to peek for parsing. For me it's too late, I got used to the C way but I still want the better thing to get adopted. No more int ((foo)(int))[5]; nonsense—just T, [N]T, or *T, making intent crystal clear.
> Yes, but unlike C's terribly confusing "declaration follows usage" style, which no tells you about btw
I happen to be reading the K&R C book right now and they do in fact tell you this.
Well it's been lost on every C online tutorial I guess
I have not read it so that's on me I guess
Yeah, not sure where that came from. The ANSI C standard was extensively documented in books and articles and specs at all levels of rigor starting from the mid-80's. No one has ever lacked for a reference for how function pointer declaration looks.
That said, C's function pointer declaration syntax is indeed awful. But really that's because ANSI took a very hardline "no incompatible changes" tact when adding prototypes to the language, which limited the ways they could express them. That decision is one of the reasons we're still writing C today. Any yahoo can come up with a new language, kids do it all the time. ANSI's job was to add features to the language in which Unix was already written.
I wonder why they went that route. At this point in my career the first notation is ingrained in my head. The bottom looks like regex.
So.. is a double dereference..
Yes
FTA: “power.* is how we dereference a pointer“
This Is basically the gist of the article.
I’m surprised to see that so many programmers these days don’t know C and basic pointers.
Why would you?
Large parts of the industry does really work with low(er) level languages.
Even people who went through C/C++ in their formal education/start of their career may have not used it for a long time.
Everyone who knows pointers had to learn them at some point.
Are you honestly surprised?
Good compiler, poor syntax. I'm waiting for the TypeScript equivalent for Zig.
Do you find it poor just because it doesn't align with your experience and bias you hold from writing other languages?
Have you looked at C3? Its goals align with Zig but it’s much closer to C in terms of syntax.
Probably a nitpick but
Didn't read, got bored at having pointers explained, even if actively trying to skip it.
I get a mix of: 1- you don't know your audience or are trying to cater to too wide of an audience
2- if someone doesn't know how pointers work, is there any merit in knowing syntax of a novel programming language?
So if you want the veterans to read this, you are going to have to make it less accessible.
Edit: it seems like the whole article is OP discovering pointers but zig is like his first language. Lol.
Hey I started using Zig after a decade of JS/Elm/Haskell/php/scala, such articles are very useful to me. Haven't used lower lever languages in a long time.
You aren't always the audience, it's fine.
This is the HN caveat.
Makes sense, it seems like you missed languages with pointers.
I would suggest going through C. Otherwise it's like learning C++ without learning C. Zig is similarly a successor to C, (it is phonetically named after it).
That would address your blind spots and let you appreciate Zig's identity
Learn C so you can avoid beginner content on Zig /s.
You're making many wrong assumptions at the same time:
- that I've never used C or C++ (both wrong)
- that I don't know pointers (also wrong, nor it is a particularly difficult topic)
- that you need to go through C again to learn Zig. Have you met many people that picked up Zig as their first programming (or first system programming) language to make those statements?
Because I am in both the IRC and discord and there's plenty of people that get proficient in Zig starting from it.
I don't understand the snark. Is it not possible to write articles for beginners? There are also a lot of developers who have never dealt with memory allocation and are interested in Zig.
Yes it is possible to write articles for begginners, but they should be on begginner concepts.
Writing about an advanced concept catering to begginners is a mess. It's like writing about logarithmic calculus and prefacing with an explanation on exponents.
That's the impression I got too.
However, thinking long term, are we going to continue to introduce pointers via C to new students? If not, then how? C++ or Zig seem viable options, so this might be a long term proposition.
Inb4 there won't be programmers
It's an interesting question.
I first don't see a problem with C being a basal part of the curriculum for centuries, we are already at half a century going strong.
Second, if this were to happen, it should happen with a mature language, and decided consciously by seasoned professionals.
Third. I think more than looking at other languges we should look into other types of pointers, like files, hyperlinks, assembly addresses, inodes.
To date C is the standard for pointer-pointer syntax, introducing new standards is fine, but it only makes sense with the standard syntax.
It's the canon of programming. Long live C
Rust would be an option as well
Not at all, rust is more a successor to C than a replacement.
Rust does not in fact have a good way to introduce raw pointers that can be passed around, and can also be treated as addresses.
Sorry, in what language can you treat pointers as just addresses? Sure, assembly, but beyond that. Maybe Pascal?
Everything else has provenance rules and magic unrepresented metadata around it that makes a pointer more than just an address.
Type (and word length as a derivate of it) anything else?
Doesn't seem hidden to me
I definitely remember casting pointers to ints and printing them to prove to myself what it was pointing to and what the offset was for the next value e.g. in an array.
In C you can also do those fun array indexing and pointer arithmetic tricks that require you truly understand the concept of "address plus offset" that basically everything uses.
But even if that's a hallucination, Rust does the hard work of keeping pointers off your mind by a combo of refs, box, etc. and Rust is not a good first language, I don't think, for a variety of reasons.
My ultimate programing curriculum if I had to make one would teach you to program in python, then show you C via Cython or similar. Lots of allocation and free under the hood in Python.
Casting pointers to ints is generally safe (at least as long as you use intptr_t instead of assuming that the size of pointers will never change).
The issue comes when you try casting to pointers. Because of providence, aliasing rules, and a couple of dragons that built a nest in the C language specification, you could have two pointers to the exact same memory locations, but have the program be undefined if you use the wrong pointer.
Granted, this doesn't stop you from doing things like
And in the few occasions where that is something you would reasonably want to do it does more or less what you would expect (unless you forgot that the CPU sticks a transparent cache between you and the memory bus; but not even assembly would save you from that oversight).Provenance (outside programming this is the distinction between "I reckon this old table is a few hundred years old" and "Here is the bill of sale from when my grandfathers ancestors had the table made from the old tree where that cherry tree is now in 1620") not Providence.
In Rust pointer provenance is a well defined language feature and if you go to the language docs you can read how it interacts with your use of raw pointers and the twin APIs provided for this.
In C the main ISO document just says basically here be dragons. There's an additional TS from 2023 with better explanation, but of course your C compiler even if it implemented all of C23 needn't necessarily implement that TS. Also of course the API is naturally nowhere near as rich as Rust's. C is not a language where pointers have an "addr" method so they also don't need a separate exposure API.
I suspect that in Zig none of this is clearly specified.