alt Hacker NewsThis is badly wrong.
• WebAssembly is not huge. Fundamentally it’s generally smaller than JavaScript, but JavaScript comes with more of a standard library and more of a runtime, which unbalances comparisons. If you use something like Rust, it’s not difficult to get the basic overhead down to something like 10 kB, or for a larger project still well under 100 kB, until you touch things that need Unicode or CLDR tables; and it will generally scale similarly to JavaScript, once you take transport compression into account. If you use something like Go or .NET, sure, then there’s a heavier runtime, maybe a megabyte, maybe two, also depends on whether Unicode/CLDR tables are needed, and then JS will probably win handily on bundle size and startup time.
• JavaScript can’t execute while it’s downloading. In theory speculative parsing and even limited speculative execution is possible, but I don’t think any engine has tried that seriously. As for WebAssembly, it can be compiled and instantiated while streaming, generally at a faster rate than you can download it. The end result is that in an apples-to-apples comparison WebAssembly is significantly faster to start than JavaScript.
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Just to correct slightly, I suspect most people who write Go WebAssembly are using https://tinygo.org/, which also achieves starting binaries in the 10kb range.
I think you're understating the cost of having to ship your own standard library with every wasm application - the chunk of stdlib used by a real app is bigger than 10kb. ICU data files are in the tens of megabytes, TZDB is a chunk of data too.
Lots of people pretend they don't need ICU or TZDB but that means leaving non-english-speakers or people outside of the US in the cold without support, which isn't the case for JS applications.
I still think this is a major unsolved problem for WebAssembly and I've previously raised it. I understand why it's not solved though - specifying and freezing the bitstream for ICU databases is a big task, etc.
>WebAssembly is not huge
I always feel like I'm downloading megabytes of it whenever someone uses it. In practice it is. Even a basic hello world in rust will set you back a few megabytes compared to a the tens of bytes it takes in javascript.
>JavaScript comes with more of a standard library and more of a runtime, which unbalances comparisons.
Being able to make programs in a few bytes is a legitimate strength. You can't discount it because it's an effective way javascript saves size.