4 ms·

Mind explaining a bit more here why Rust is a particularly good language to compile to wasm? Why does memory safety help here? Asking out of ignorance!

by iMuzz 6y ago

sanxiyn 6y ago
Mostly because WebAssembly does not include GC yet, so being a non-GC language helps.
esperent 6y ago
From what I understand, this mainly means that a lot of work has been put into making this process possible, while for some other languages the workflow to wasm is lacking.
jkelleyrtp 6y ago
There aren’t very many good wasm options that will produce web-friendly binary sizes. The options are really c/c++, rust, and some other less-supported languages like Zig and Nim. Rust has a good mix of high-level constructs (making it more productive than C) and has a good ecosystem around it. Cross compiling is never easy, and the rust wasm story is arguably the best and most supported via wasm-bindgen.
gboss 6y ago
WASM doesn’t have a garbage collector built in. Languages that use a garbage collector have to also convert their language runtime into WASM which can dramatically increase the WASM file sizes and is more work to process by the browser. Since rust doesn’t have a garbage collector this should make its WASM files smaller and more performant
connicpu 6y ago
There isn't necessarily any inherent thing about the language itself that makes it better at WASM than others, it's more that it was one of the first languages that was ready for WASM. - It's low level like C and C++ so it maps cleanly onto WASM - In your average Rust project, all dependencies are already built from source, greatly increasing the likelihood all your dependencies can be built for WASM - Already using LLVM as the compiler backend made WASM targeting a lot less work than for languages that need to do that work from scratch - Probably most importantly, a lot of developers involved in core rustc development were motivated to get Rust working on WASM At least that's my perception for how Rust became such a prominent language for WASM development early on
- jillesvangurp 6y ago
  You forgot the most important thing: it doesn't need a garbage collector. This is important because wasm garbage collection is a work in progress. The solution other languages targeting wasm typically use is bundling their own garbage collector in the compiled code, which of course adds a bit of code bloat. E.g. C# blazor wasm applications are not exactly small for this reason. There was a message yesterday in the Kotlin slack about them starting work on a wasm compiler backend for Kotlin (they already have java, native, and js compilers). https://github.com/JetBrains/kotlin/tree/master/compiler/ir/backend.wasm https://github.com/JetBrains/kotlin/tree/master/compiler/ir/... Interestingly they plan to depend on the wasm GC proposal instead of bundling their own: https://github.com/WebAssembly/gc/ https://github.com/WebAssembly/gc/ So, things are improving on this front. But it's a big reason why Rust is particularly popular for wasm right now because they have no GC and lots of developer tools that are relatively mature because they've been working on this for a while. IMHO, this will take another few years to fully mature but inevitably lots of people are going to be writing web applications that don't involve any or very little javascript. Kotlin is starting to look very solid for any kind of cross platform Android, IOS, and web based development (as well as server development, which is what I do). Swift would be another candidate and there already is a wasm compiler for that as well.
  - rhlsthrm 6y ago
    Interesting, one of the big reasons I want to learn Rust is to "future proof" myself once JS loses its monopoly on the web. Maybe Kotlin will be a better one than Rust?
- jfkebwjsbx 6y ago
  > - In your average Rust project, all dependencies are already built from source That is only the case for open source code like crates.io, there is nothing that guarantees you will get the source code of a third-party, though. I mention this because in the native world it is common to give customers precompiled libraries. > - Already using LLVM as the compiler backend Some people don't seem to know this, but all languages that target LLVM (including C, C++, Fortran, Ada, Julia, Swift and others) can be used in WebAssembly.
fulafel 6y ago
Wasm is not memory safe inside the sandbox, so the language should enforce it if you care about correctness and/or dislike the C/C++ memory bugs and debugging.

Mind explaining a bit more here why Rust is a particularly good language to compile to wasm? Why does memory safety help here? Asking out of ignorance!

by iMuzz 6y ago

Mind explaining a bit more here why Rust is a particularly good language to compile to wasm? Why does memory safety help here? Asking out of ignorance!

sanxiyn 6y ago

Mostly because WebAssembly does not include GC yet, so being a non-GC language helps.

esperent 6y ago

From what I understand, this mainly means that a lot of work has been put into making this process possible, while for some other languages the workflow to wasm is lacking.

jkelleyrtp 6y ago

There aren’t very many good wasm options that will produce web-friendly binary sizes. The options are really c/c++, rust, and some other less-supported languages like Zig and Nim. Rust has a good mix of high-level constructs (making it more productive than C) and has a good ecosystem around it. Cross compiling is never easy, and the rust wasm story is arguably the best and most supported via wasm-bindgen.

gboss 6y ago

WASM doesn’t have a garbage collector built in. Languages that use a garbage collector have to also convert their language runtime into WASM which can dramatically increase the WASM file sizes and is more work to process by the browser. Since rust doesn’t have a garbage collector this should make its WASM files smaller and more performant

connicpu 6y ago

There isn't necessarily any inherent thing about the language itself that makes it better at WASM than others, it's more that it was one of the first languages that was ready for WASM. - It's low level like C and C++ so it maps cleanly onto WASM - In your average Rust project, all dependencies are already built from source, greatly increasing the likelihood all your dependencies can be built for WASM - Already using LLVM as the compiler backend made WASM targeting a lot less work than for languages that need to do that work from scratch - Probably most importantly, a lot of developers involved in core rustc development were motivated to get Rust working on WASM At least that's my perception for how Rust became such a prominent language for WASM development early on

jillesvangurp 6y ago
You forgot the most important thing: it doesn't need a garbage collector. This is important because wasm garbage collection is a work in progress. The solution other languages targeting wasm typically use is bundling their own garbage collector in the compiled code, which of course adds a bit of code bloat. E.g. C# blazor wasm applications are not exactly small for this reason. There was a message yesterday in the Kotlin slack about them starting work on a wasm compiler backend for Kotlin (they already have java, native, and js compilers). https://github.com/JetBrains/kotlin/tree/master/compiler/ir/backend.wasm https://github.com/JetBrains/kotlin/tree/master/compiler/ir/... Interestingly they plan to depend on the wasm GC proposal instead of bundling their own: https://github.com/WebAssembly/gc/ https://github.com/WebAssembly/gc/ So, things are improving on this front. But it's a big reason why Rust is particularly popular for wasm right now because they have no GC and lots of developer tools that are relatively mature because they've been working on this for a while. IMHO, this will take another few years to fully mature but inevitably lots of people are going to be writing web applications that don't involve any or very little javascript. Kotlin is starting to look very solid for any kind of cross platform Android, IOS, and web based development (as well as server development, which is what I do). Swift would be another candidate and there already is a wasm compiler for that as well.
- rhlsthrm 6y ago
  Interesting, one of the big reasons I want to learn Rust is to "future proof" myself once JS loses its monopoly on the web. Maybe Kotlin will be a better one than Rust?
jfkebwjsbx 6y ago
> - In your average Rust project, all dependencies are already built from source That is only the case for open source code like crates.io, there is nothing that guarantees you will get the source code of a third-party, though. I mention this because in the native world it is common to give customers precompiled libraries. > - Already using LLVM as the compiler backend Some people don't seem to know this, but all languages that target LLVM (including C, C++, Fortran, Ada, Julia, Swift and others) can be used in WebAssembly.

fulafel 6y ago

Wasm is not memory safe inside the sandbox, so the language should enforce it if you care about correctness and/or dislike the C/C++ memory bugs and debugging.