Not GP, but I've written game engines and rendering engines. Vector operations are just common enough that having to write `.mul` every time is a huge pain, especially when you put many of them together for a large formula. Compare:
We learn to read and think about math a certain way, which is incompatible with Zig. Also, Zig's design philosophy of "reading code over writing code" is incompatible with the kind of small modification-test-cycles required when doing games, and creative programming in general. So Zig is sort of DOA anyway for that kind of thing.
But I've been using Zig for non-game projects and it's been fantastic, so definitely not "Blind leading the blind" for the overall language design, imo.
I know this is already possible with comptime, though I haven't implemented it yet since I haven't needed vector math in what I'm working on currently. Can't decide whether using math names is better or worse than using the full variable names though.
I have a sibling comment -- having thought about this for a very very long time, zig should really implement binary pseudo-operator syntactic sugar. I don't think this violate zig's spirit of 'no hidden function calls' in that I don't think it takes much of a mental lift to "get" that (_ <+> _) means "heyo this is a function call, not a true operator".
At first I was going to say that I disagreed since you couldn't choose what implementation of addition you wanted, but now that I've read your comment where you import the type of addition used, it's growing on me. Would you have operator precedence, or would it be more like Smalltalk's binary operators?
Andrew talks about it because it introduces hidden control flow where you're expecting simple operators. In Zig anything that deals with control flow is a keyword (including short circuiting and, which is `and` instead of `&&`).
I'd argue though that the real disadvantage to having overloadable arithmetic is that you're limited to one implementation. This is actually my biggest beef with Rust, namely traits/type classes. It locks you into a single implementation when you may want to do something different based on the context. Zig pushes the dispatch decision to the callsite, not a trait subsystem (see how Zig implements hash mays for example). So I'd personally prefer to use a DSL, since it lets me specify what type of dispatch to use.
Overloadable operators are not an instance of hidden control flow. Overloadable operators represent a user-defined function call, and thus can't influence control flow any more than a regular function. And if regular functions can't do anything weird to control flow (e.g. if your language already lacks exceptions (or even weirder things like Ruby-style procs)), then overloadable operators can't either.
> It locks you into a single implementation when you may want to do something different based on the context.
If you want differing behavior in a certain context, and if you don't want to use a different method to make the differing behavior explicit (e.g. the `wrapping_add` methods that Rust provides on numeric types), then you can use a different type for that context, e.g. the `std::num::Wrapping` type that Rust provides.
> Overloadable operators are not an instance of hidden control flow.
In general perhaps not, but in Zig it definitely does. Zig considers calling a function to change control flow, because it's no longer just an operator but something that can cause side effects, includinh mutating in place. Perhaps control flow isn't the right term, maybe non-trivial would be better?
With regard to wrappers, I personally find them ugly since 1. They bring in indirection, and I have a personal vendetta against unnecessary indirection, 2. Wrapping doesn't compose well and is a pain to shephard between representations, 3. It's harder to make a function generic across different representations, and 4. Wrappers often don't re-export everything available to their underlying value.
It's appealing to people who want to understand and control everything they're doing. When I'm using pandas or SQLAlchemy, I have no idea what the code is actually doing. Most people don't care about such implementation details, but some people do.
yes! i had this exact idea. i also thought about integrating geometric/clifford algebra using zig's type system so that you could have one mathematical multivector object instead of complex / quaternion types, etc.
That's the other great thing about using comptime, is you can specify which DSL you want to use for which scenario. You're not locked into one implementation.
For me the answer is very simple: Operators make it easier to read the code which makes it easier to spot bugs. It also makes it easier to turn formulas from textbooks into code.
If 50% of the code you're working with is using vectors and matrices, not having operators for those parts is quite annoying.
Note that you can have vector operators without overloading, e.g. Odin has built in vector and matrix types.
But personally I think it's better to give the user more power instead of only letting the compiler author pick which types to allow operators on. Like how Java overloads + but only on the String class. Why do they get to do it, but not me?
you actually don't want "operator overloading", you want syntactic sugar. I once proposed just a special operator syntax at the parser level, but it got rejected, but if you REALLY wanted it, you could probably do this in about 100-120 lines as a fork of the zig compiler, just hacking (a <_> b) as a special form to be transformed into @"<_>"(a, b). Requiring parentheses elides questions about operator precedence.
const @"<+>" = @import("operator_module").plus;
...
const x = (a <+> b);
I think both operator overloading and most operators themselves are syntactic sugars. Operator overloading happens to point towards specific functions, whereas arithmetic integer operators point to compiler intrinsics.
no, in general overloading is not syntactic sugar, it's a feature of the language (being able to (re-)define a function in place X and have it change the function in unrelated place Y).
I don't see how it is unrelated. If have a custom type `A` with an overload on `+`, it will only affect places I used custom type `A`. If there wasn't operator overloading, I would just have to use a different notation to call the same function, but with possibly worse ergonomics (which is also why I think your solution doesn't really satisfy that, it doesn't read like algebra which is kind of the point). Given that type A is presumed to be custom, I don't see how place Y would be unrelated since it deliberately uses type `A`.
If we include operator overloading for any types, then sure. i32 + i32 might suddenly start meaning something else. But I think that's beyond the scope of what is normally asked by operator overloading.
Yes it is control flow, but IMO it's not hidden. It's true that you need to learn that * happens before + (which usually happens in school), but I don't see how that's any different from needing to learn that `and` short-circuits, or that `if` only evaluates its body if the condition is true.
Compare to what people usually call hidden control flow (exceptions, RAII, ...) where you don't know which parts of the code will run unless you read the definitions of the classes and bodies of the functions you use. The syntax at the call site is not enough to tell.
I mean as an avid Lisp fan, I feel like Lisp basically answers the question of how much syntax you need in a langauge. I must admit though, not having to deal with operators precedence is really nice
1> let ((x 3) (step 2) (width 5)) ((2 * step + x) mod width)
2
This is TXR Lisp with auto-infix and auto-compound enabled for the REPL:
2> *listener-auto-infix-p*
t
3> *listener-auto-compound-p*
t
So we can omit the outermost parentheses, and infix syntax is automatically recognized, freely intermixed with regular Lisp, as if the (ifx ...) macro were wrapped around the input.
I've come up with a very good way of handling infix in Lisp, and documented it in a decent amount of detail as well, not just as a manual for the user but anyone wanting to implement something similar.
Regarding operators, there are 3 distinct problems.
One is to allow the use of simple mathematical symbols as names for functions, instead of allowing only alphanumeric identifiers.
Most programming languages allow only a small fixed set of symbols to be used as "operators", i.e. as function names.
The better solution is to allow any Unicode character from certain categories, e.g. "Sm" and "Po" ("Symbol, math" and "Punctuation, other"), which does not have an already assigned role in the language syntax, to be used as a function name.
Most LISP variants allow the use of various kinds of character symbols as function names.
The second problem is overloading. Overloading must be treated uniformly for any kind of functions, regardless if their names are identifiers or operator symbols, i.e. not like in Java, where forbidding operator overloading was a mistake (that was an overreaction to C++, which allows the overloading of a few "operators" that are not normal functions and whose overloading should not have been allowed, e.g. the comma operator).
The overloading of operators, especially for user-defined data types is something absolutely essential for scientific and technical computing.
The majority of programmers have not been exposed to programs that contain a great amount of computations, so they are accustomed only with simple expressions that contain a few variables.
In scientific and technical computing it is very frequent to have very big expressions, which may contain a large number of operations and variables, where the variables may have various types, like complex numbers, vectors, matrices, complex vectors, complex matrices, or there may be a type system with distinct types for various physical quantities, like voltages, electric currents, capacitances and so on.
Anyone who had to write frequently such big expressions will definitely prefer, both for writing and for reading, to use overloaded operator symbols instead of long function names, which would fill most of the visual space with superfluous characters, obscuring the structure of the big expression.
The third problem is the syntax of function invocation. Most programming languages allow functions whose names are identifiers to use only prefix invocation but for some symbolic operators they allow infix invocation.
Here I also prefer the languages that do not differentiate between functions with alphanumeric names and functions with symbolic names (i.e. operators). There are languages where for any function it may be specified that it must be invoked as an infix operator, if this is desired.
Which is the best between the 3 classic solutions for expression syntax, traditional expressions with infix operators and multi-level precedence rules (like in FORTRAN and ALGOL), expressions with infix operators and a unique precedence rule for all operators (like in APL) and expressions without infix operators (like in LISP), is debatable.
Each of the 3 solutions has advantages and disadvantages, so the choice between them is a matter of personal preferences.
(physics_data.velocity + omega * change) * frame_delta_time
to
physics_data.velocity.add(omega.mul(change)).mul(frame_delta_time)
We learn to read and think about math a certain way, which is incompatible with Zig. Also, Zig's design philosophy of "reading code over writing code" is incompatible with the kind of small modification-test-cycles required when doing games, and creative programming in general. So Zig is sort of DOA anyway for that kind of thing.
But I've been using Zig for non-game projects and it's been fantastic, so definitely not "Blind leading the blind" for the overall language design, imo.