Where is the .wasm?

[jymchng]

Hi, thank you for your hard work on this playground.

I am interested to build a Go playground as well with WASM, I see that you guys are using WASM execute arbitrary Go 1.22 codes, I am curious to know where is the .wasm binary for this.

Thank you.

[x1unix]

Hello @jymchng

WASM binary is built on a server and then served to a user for execution.
Under the hood, API serves a cache or otherwise - runs go build to build a WASM program.

See:

• Backend:
  • https://github.com/x1unix/go-playground/blob/master/internal/server/handler_v2.go#L200 - HTTP handler
  • https://github.com/x1unix/go-playground/blob/master/internal/builder/compiler.go#L85 - Builder business logic
• Frontend:
  • https://github.com/x1unix/go-playground/blob/master/web/src/store/dispatchers/build/dispatch.ts#L127

P.S - Previously we had a in-browser Go interpreter based on Yaegi but it was removed as project is not actively maintained and doesn't support modern Go features like generics.

In future we plan to move Go compiler completely into a browser but this is a complex task.

[jymchng]

Hello @jymchng

WASM binary is built on a server and then served to a user for execution. Under the hood, API serves a cache or otherwise - runs go build to build a WASM program.

See:

• Backend:

  • https://github.com/x1unix/go-playground/blob/master/internal/server/handler_v2.go#L200 - HTTP handler
  • https://github.com/x1unix/go-playground/blob/master/internal/builder/compiler.go#L85 - Builder business logic

• Frontend:

  • https://github.com/x1unix/go-playground/blob/master/web/src/store/dispatchers/build/dispatch.ts#L127

P.S - Previously we had a in-browser Go interpreter based on Yaegi but it was removed as project is not actively maintained and doesn't support modern Go features like generics.

In future we plan to move Go compiler completely into a browser but this is a complex task.

Yeah, moving the entire Go compiler into the browser is very difficult although I don't fully understand it. I had asked TinyGo this question before and they replied it is the CGo part of the compiler that is blocking them.

[x1unix]

I had asked TinyGo this question before and they replied it is the CGo part of the compiler that is blocking them.

If you're doing WASM builds - you can throw away cgo part. Probably writing own compiler based on original Go compiler will be more simple approach, as go build calls a lot of commands under the hood and getting exec.Cmd working in browser is complicated.

If you're looking for an easy path and don't need generics - Yaegi might be suitable for you.

[jymchng]

Thank you for your reply. @x1unix

Essentially, what you're saying is the code execution actually uses the actual Go compiler to compile the source files on the playground into a .wasm binary and execute the .wasm binary. There's isn't an in-browser .wasm binary that is responsible for compiling and executing the .go source files on the playground.

Is my interpretation accurate?

[x1unix]

Yes, correct. All compilation is happening on server.