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Comment by mrashes | Hacker News Reader

I really love the idea of WebAssembly but am super intimidated by it. Being a junior frontend dev it seems like a really powerful piece of tech that could go in a million directions in the future.

My big hangup is understanding a low level use case for it. I've console.logged in wasm but only knowing javascript I don't know where to go from here. Is the idea that you can utilize packages in any language then rebuild it in js?

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If you are a junior frontend developer, WASM probably just doesn't mean much to you, and probably won't. You'll use it, wrapped by a JavaScript facade, to do some performance-sensitive stuff. (Some folks are rubbing their hands together about the possibility of using the DOM in another language and not writing JavaScript; this will eventually happen, but I strongly doubt mainstream frontend development will go that way in the reasonably near future.

I don't really see why you should be intimidated by it any more than a Java programmer who sees JNI barf once in a while should be intimidated by C. If you're that interested, all you really have to do is learn a normal, natively-compiled language. Which would be wise anyway--nobody serious about the field should only know one language, JavaScript or not. Then you can learn how to compile down to WASM (it's rarely difficult) and just go from there.

It's intimidating because the tooling is very immature. Compiler and debugger support is not at the level of Java or C.

> Compiler and debugger support is not at the level of Java or C.

WASM is more of a compiler target, not a language at the level of C or Java: its something you'd compile to from C.

That doesn't forbid WASM to have a nice graphical debugger, like most CPUs have.

WASM can already be debugged with the browser-integrated debuggers, source maps can map back to the original files.

Yeah, I've been working on python and java for sometime but it still boils down to js thinking for me.

Thanks for explanation though, I'm not intimidated of it taking my job as much as I am the wide scope of the thing. Seems massive!

I dunno. It's no more massive than most other computing environments. JavaScript is an aberration in the way it's structured. This is certainly a matter of perspective; I tend to think that starting with a restrictive environment like JavaScript (and don't get me wrong, I like JavaScript and write a decent bit of it every day) makes the cage look like the world. Pedagogically speaking, I worry about JavaScript being somewhat damaging...but, whatever.

Anyway, WASM is just trying to remove the restrictions on a strict environment (that's why it's called Web Assembly, yeah?). The example that floated to mind--you've been writing Java? This[1] is written in Clojure, but there's no reason you can't get this wacky in Java. (Not that you should.)

[1] - https://aphyr.com/posts/341-hexing-the-technical-interview

> Some folks are rubbing their hands together about the possibility of using the DOM in another language and not writing JavaScript; this will eventually happen

Sadly WASM doesn't help here at all due to lack of way to interact with the GC. Not only lack of finalisers but that having two GCs doesn't work. I learnt this 2 times over the hard way.

For something today, look to fengari: https://fengari.io/ . It implements a VM in javascript, reusing the javascript garbage collector, which means that you get seamless DOM interaction.

In time. Model the WASM code as a WebWorker, use the DOM like you would in React. A semantic level shadow DOM in WASM is lightweight.

WASM is a beautiful baby universe, hatched from a messy past.

GC interaction is not needed for DOM stuff. That was originally the case, but the "host bindings" proposal lets it shed that dependency. I pasted a link downthread.

From my understanding one use case is Transpiling into Web Assembly. The tooling isn't there yet, but you can hopefully use it instead of JavaScript and get some type safety and performance.

Sure you can use a language like TypeScript or one of the others that will transpile down to JavaScript giving you type safety, but you won't have the performance of web assembly. Although, I've yet to see what you'll need that performance for. A few of my co-workers are excited about it, but I've been pressing them, we don't need that level of performance on the SPA type stuff we write.

I think having web assembly will give you new avenues and use cases people haven't fully considered yet.

It's actually compiling to wasm..no more transpilling

Sorry, I wasn't clear. So instead of writing WebAssembly, you can write another language such as C# that will get compiled into wasm.

With enough luck and given time you will be able to skip JS at all! If the community will find the life force after wasting many years on SPA, then we might even see some HTML—near-free canvas/WebGL GUIs!

Yep, like this one - https://pbrfrat.com/post/imgui_in_browser.html

Microsoft is already doing it with .NET, others as well.

Expect the revenge of browser plugins.

no way a .net plugin become mainstream, thankfully we left behind java-like-plugins.

Sorry to disappoint you, but everyone is on the WebAssembly race, all plugins will be back, like it or not.

https://github.com/appcypher/awesome-wasm-langs

https://github.com/mbasso/awesome-wasm

As for Microsoft, they just announced the Blazor project.

https://blogs.msdn.microsoft.com/webdev/2018/02/06/blazor-ex...

Thank browser developers for opening the pandora box.

I am not a fan of this. Browsers by now have awesome text layout and rendering support, highlighting, screen reading, zooming. Individual images can be seen/copied/saved, user scripts and styles and browser plugins can access the loaded html content, and so on.

All this will have to be redone in canvas for no good reason and I doubt it will be nearly as good as what browsers can do already, and we will lose a lot of openness and interop.

While I agree that we may be able to rid ourselves of JS, why would we want to rid ourselves of HTML? It's become an excellent language for describing a UI.

> My big hangup is understanding a low level use case for it.

Two real world use cases for WebAssembly are image decoding and audio decoding.

WebP image decoding: https://webmproject.github.io/libwebp-demo/webp_wasm/index.h...

Opus audio decoding: https://www.scirra.com/blog/211/opus-audio-in-construct-3

Emulating entire computers: http://blog.archive.org/2018/02/13/emulation-in-the-browser-... This is powerful because it makes the emulator itself platform-independent. Any wasm-capable browser can now emulate a ton of other platforms.

Alternatively you could compile proprietary desktop applications to webasm and use nodejs as a standalone VM.

I hadn't thought about using it for decoding images, clever! I'd been dreaming of translating my favorite python package over to the web to use without having to spin up django, but from what I'm hearing that isn't really the purpose.

We're not quite ready yet, but later in the year, you should check out Rust and wasm. We explicitly are interested in catering to the "am super intimidated by it" case. Right now, it all works, but is not super nice to use; it's under really heavy development though!

Perspective is a good example: https://github.com/jpmorganchase/perspective

Move heavy number crunching into WASM.

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