Comment by yellowapple
3 days ago
What's stopping Julia from being reasonably usable to make actual applications? It's been awhile since I've touched it, but I ain't seeing a whole lot in the way of obstacles there — just less inertia.
3 days ago
What's stopping Julia from being reasonably usable to make actual applications? It's been awhile since I've touched it, but I ain't seeing a whole lot in the way of obstacles there — just less inertia.
Presumably inertia and ecosystem size (but that's a follow on of inertia). When Julia came out Python already had traction for ~most things.
Keep in mind that it went with 1 based indexes to make the switch easy for Matlab types. I'm not sure if that was a good or bad move for the long term. I'm sure it got some people to move who otherwise wouldn't have but conversely there are also people like me who rejected it outright as a result (after suffering at the hands of 1 based indexing in Matlab I will never touch those again if I have any say in the matter).
I've considered switching to it a few times since seeing that they added variable indexes but Python works well enough. Honestly if I were going to the trouble of switching I'd much rather use Common Lisp or R5RS. The nearest miss for me is probably Chicken, where you can seamlessly inline C code but (fatally) not C++ templates.
If I ever encounter "Chicken, except Rust" I will probably switch to that for most things.
That's part of the answer, but there's a bit more to it IMO.
The syntax is a bit weird; python, swift, rust, and zig feel more parsimonious.
I absolutely love multimethods, but I think the language would have been better served by non-symmetric multimethods (rather than the symmetric multimethods which are used). The reason is that symmetric multimethods require a PHD-level compiler implementation. That, in turn, means a developer can't easily picture what the compiler is doing in any given situation. By contrast, had the language designers used asymmetric multimethods (where argument position affects type checking), compilation becomes trivial -- in particular, easily allowing separate compilation. You already know how: it's the draw shapes trick i.e., double-dispatch. So in this case, it's trivial to keep what compiler is "doing" in your head. (Of course, the compiler is free to use clever tricks, such as dispatch tables, to speed things up.)
The aforementioned interacts sensitively with JIT compilation, with the net outcome that it's reportedly difficult to predict the performance of a snippet of Julia code.
Just to clarify the above:
1. I use the term "performance" slightly vaguely. It's comprised of two distinct things: the time it takes to compile the code, and the execution time. The issue is the compilation time: there are certain cases where it's exponential in the number of types which could unify with the callsite's type params.
2. IIRC, Julia compiler has heuristics to ensure things don't explode for common cases. If I'm not mistaken, not only do compile times explode, but certain (very common) things don't even typecheck. There's an excellent video about it by the designer of the language, Jeff Bezanson -- https://www.youtube.com/watch?v=TPuJsgyu87U . Note: Julia experts, please correct me if this has been fixed.
3. The difficulty in intuiting which combinations of types will unify at a given callsite isn't theoretical; there are reports of libraries which unexpectedly fail to work together. I want to qualify this statement: Julia is light years ahead of any language lacking multimethods when it comes to library composability. But my guess is that those problems would be reduced with non-symmetric multimethods.
4. The non-symmetric multimethod system I'm "proposing" isn't my idea. They are referred to variously as encapsulated or parasitic multimethods. See http://lucacardelli.name/Papers/Binary.pdf
I have huge respect for Jeff Bezanson, for the record!
> The syntax is a bit weird
In what way? It's more-or-less the same syntax as Ruby and Elixir, just with different keywords. Like as much as I love Zig, Zig's syntax is way weirder than Julia's IMO (and none of 'em hold a candle to the weirdness of, say, Erlang or Haskell or Forth or Lisp).
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I've always thought it sad that lush died; in many ways it was a spiritual predecessor to julia. here's a nice blog post about it: https://scottlocklin.wordpress.com/2024/11/19/lush-my-favori...
I was excited about julia as an application development language when it first came out, but the language and ecosystem seem to be targeting long-running processes. there was just a ton of latency in build time and startup time for things like scripts and applications, so I moved on.
https://yuri.is/not-julia/
> My conclusion after using Julia for many years is that there are too many correctness and composability bugs throughout the ecosystem to justify using it in just about any context where correctness matters.
It's actually better suited IMO, being a compiled language. I'm not sure how anyone could consider the current train wreck of getting python code just to run "actual applications." uv is great and all, but many of these "actual applications" don't use it.