alt Hacker NewsThat old thing again ;)
Direct DOM access doesn't make any sense as a WASM feature.
It would be at best a web-browser feature which browser vendors need to implement outside of WASM (by defining a standardized C-API which maps to the DOM JS API and exposing that C API directly to WASM via the function import table - but that idea is exactly as horrible in practice as it sounds in theory).
If you need to manipulate the DOM - just do that in JS, calling from WASM into JS is cheap, and JS is surprisingly fast too. Just make sure that the JS code has enough 'meat', e.g. don't call accross the WASM/JS boundary for every single DOM method call or property change. While the call itself is fast, the string conversion from the source language specific string representation on the WASM heap into JS strings and back is not free (getting rid of this string marshalling would be the only theoretical advantage of a 'native' WASM DOM API).
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Isn’t the whole reason why people want DOM access is so that the JavaScript side doesn’t have any meat to it and they can write their entire web app in Rust/Go/Swift/etc compiled to webasm without performance concerns?
> Direct DOM access doesn't make any sense as a WASM feature.
…proceeds to explain why it does make sense…
> If you need to manipulate the DOM - just do that in JS, calling from WASM into JS is cheap, and JS is surprisingly fast too.
From the point of view of someone who doesn't do web development at all, and to whom JS seems entirely cryptic: This argument is weird. Why is this specific (seemingly extremely useful!) "web thing" guarded by a specific language? Why would something with the generality and wide scope of WASM relegate that specific useful thing to a particular language? A language that, in the context of what WASM wants to do in making the web "just another platform", is pretty niche (for any non-web-person)?
For me, as a non-web-person, the big allure of WASM is the browser as "just another platform". The one web-specific thing that seems sensible to keep is the DOM. But if manipulating that requires learning web-specific languages, then so be it, I'll just grab a canvas and paint everything myself. I think we give up something if we start going that route.
> Direct DOM access doesn't make any sense as a WASM feature.
I disagree. The idea of doing DOM manipulation in a language that is not Javascript was *the main reason* I was ever excited about WASM.
WASM is an abbreviation for WebAssembly. If it doesn't have DOM access, WebAssembly is as related to the Web as JavaScript is to Java. A language ecosystem with no I/O capability is as much use as a one-legged man at an arse-kicking party.