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Maybe you don't need Rust and WASM to speed up your JS

mrale.ph

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Re: Maybe you don't need Rust and WASM to speed up your JS

#51

Post by alangpierce »

wereHamster wrote: post #22
Too wrote: post #17

Earlier quoted context omitted.

What would you consider to be a "good type system"? I find typescript to have one of the most sane and still strict type systems of all languages that doesn't fall into the extreme functional spectrum or those that care about memory ownership.

Any language that doesn't have first-class support for ADTs is a waste of my time. And I say that as someone who's working with TypeScript all day long, and try to push it in my team, even though it sometimes requires verbose code and boilerplate. But I take that over plain JS any day. It took long enough for my coworkers to recognise the benefit of a type system. Can't push them too hard too far too quickly.

When you say ADTs, do you mean algebraic data types or abstract data types? My impression has been that TypeScript is quite good at algebraic data types (i.e. tagged unions). You need to use normal conditionals like if/switch or your own function instead of syntactic support for pattern matching, but IMO the static analysis makes it work out pretty well.

Re: Maybe you don't need Rust and WASM to speed up your JS

#52

Post by azakai »

austincheney wrote: post #11

I thought all the benchmarks indicated that WASM is still slower than JS. That being said the only performance improvements offered by WASM is if it doesn't for garbage collection for consistence execution. WASM isn't about performance. It is about writing applications in any language and importing those applications into an island in a web page.

> I thought all the benchmarks indicated that WASM is still slower than JS.

No, wasm is almost always faster than JS, and that has been the case for a while.

Maybe you're thinking about some very specific aspect of performance or benchmark? (For example, wasm->JS calls might be slower than JS->JS calls in some cases.)

Re: Maybe you don't need Rust and WASM to speed up your JS

#53

Post by alangpierce »

devit wrote: post #28
Too wrote: post #17

Earlier quoted context omitted.

What would you consider to be a "good type system"? I find typescript to have one of the most sane and still strict type systems of all languages that doesn't fall into the extreme functional spectrum or those that care about memory ownership.

It's not: the TypeScript type system is unsound (accepts code that violates it), and there are no runtime checks, so it doesn't actually guarantee anything: a TypeScript variable may in fact contain any value regardless of its declared type. I'd say the best type systems are found in Rust (naturally models zero-cost abstractions but doesn't have dependent types) and Idris and Coq (have dependent types but don't natur…

TypeScript intentionally strikes a balance between strict soundness and developer productivity, and I've personally been pretty happy with that balance. There's more to language design than soundness, and I've been happy with TypeScript's willingness to get out of my way for little snippets of unsafe code, especially when interfacing with external libraries. Within my own code, I've never had the unsoundness actually cause problems.

Re: Maybe you don't need Rust and WASM to speed up your JS

#56

Post by lmm »

Too wrote: post #17
lmm wrote: post #3

I'm excited about compiling to WASM not for performance but for correctness. Typescript is better than nothing but it really can't compete with the safety and ease you get from a language with a really good type system.

What would you consider to be a "good type system"? I find typescript to have one of the most sane and still strict type systems of all languages that doesn't fall into the extreme functional spectrum or those that care about memory ownership.

At an absolute minimum I'd want support for non-structural types and sound variance of collections; typescript also lacks real support for sum types. Honestly these days I probably wouldn't bother with a language without higher-kinded types - once you think in them it becomes very tedious to be repeating the same code over and over because your language can't express the types the code actually is.

(Really I'd like polykindedness as well. I've only needed it once in over a decade of programming but it was such an intensely frustrating experience to need it and not have it)

Re: Maybe you don't need Rust and WASM to speed up your JS

#57

Post by alangpierce »

For writing high-performance JavaScript, I'm really hoping that AssemblyScript takes off[1]. The project is still a bit in early stages, but theoretically, it can have the same role as Cython: you write JS/TS code, find the slow parts, and get perf improvements by adding stricter types to your code and changing your code to not use dynamic JS features. You can stay pretty much in JS rather than having to switch to a completely new language to get predictable fast performance.

[1] https://github.com/AssemblyScript/assemblyscript

Re: Maybe you don't need Rust and WASM to speed up your JS

#58

Post by kibwen »

faitswulff wrote: post #21
lmm wrote: post #3

I'm excited about compiling to WASM not for performance but for correctness. Typescript is better than nothing but it really can't compete with the safety and ease you get from a language with a really good type system.

One thing I've been confused with about transpiled languages is how does correctness transfer? How do types or lifetimes etc. transfer to WASM, for instance? Or does it just depend on the correctness to be verified in the pre-compilation/transpilation stages?

Unlike typical assembly, WASM enforces strong guarantees around memory safety (which I'll argue is precisely what you want for something with a web browser's attack surface). This does imply a performance hit (conventional wisdom is that WASM will, at best, be half as fast as "native" code), but also insulates the user from the usual memory-related pitfalls of C. Code transpiled from Rust is forced to pay this price as well, despite Rust providing substantially stronger memory safety guarantees than C; fortunately if you're using Rust you'll probably be the sort of person who agrees that this is a good thing, because Rust still lets one drop into unsafe blocks and potential memory unsafety in untrusted code delivered over the network is pretty much a nightmare scenario.

Re: Maybe you don't need Rust and WASM to speed up your JS

#59

Post by sametmax »

petre wrote: post #41
sametmax wrote: post #20

Earlier quoted context omitted.

When JS came out, it was poorly designed, but nobody cared because we used it only to make snowflakes appear on the web page. Then MS gave us AJAX and 37 signals made it popular, until apps like gmail made it so mainstream it was impossible to go back to old static pages. But it was too late. The shitty language we had was the only one available everywhere to do dynamic web pages now. IE would not move, and Firefox a…

> So instead of implementing a better language, they also used JS They did implement a better language, Dart. But it was too late, like you said. Maybe we'll have a change of using it for mobile apps with Flutter.

Dart came way, way later. And it was a new language, while they could have just used an existing one. They could have implemented lua, ruby, Python, anything with a good track record. With the millions spent on V8 with those geniuses working on it, can you imagine how fast one of those language would have become ? The tooling it would have had ?

Re: Maybe you don't need Rust and WASM to speed up your JS

#60

Post by patientplatypus »

So...

I'm a (junior/so-so) react dev. I like the language, I probably could get better at it but I've gotten to the point where I like the sound of my own music.

That said, my question is the following. There seems to be a lot of resources on the web of the type "Hey Rust and WASM is a thing! You can make webpages with it". Ok, fine. However, I don't see a lot of the things that are in libraries like Vue and React that offer me SPA, fast development time and component (OR!) functional pattern design (I won't mention the ability to add npm packages, because yeah, Rust/WASM doesn't have an ecosystem yet, so that might be punching a bit below the belt). Is there anyone out there making a React like or "eco-system builder"-esque platform that would give me a lot of the benefits I'm seeing with React but with increased performance?

Also, I've done some low level programming before and think that Rust is very cool for that (yay memory safety! yay error messaging (no seriously yay)!). However, and I may be betraying my ignorance here, if I want to animate a div to fly across the page, am I going to have to write lots of low level code to do that? If that's the case, and development time suffers to eek out that extra bit of performance, I can't see this as having much utility outside of niche fields like game development.

I don't mean to be overly critical mind as I'm still (and probably will always be) a bit of a n00b. I'd love it if somebody would point me at some resources that I could burn a weekend on, if I thought the juice was worth the squeeze. I'm just not sure I know enough to know if this is something that I could be productive in (some day).

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