Get Going with WebAssembly

15th August 2018

Today we will

• Learn about WebAssembly (WASM)
• Learn to use WASM from Go
• Show what is possible today
• See what will be possible tomorrow

WebAssembly

• Web standard binary executable format
• Cross browser
• JavaScript interface

GopherJS

• Tool for compiling Go to JavaScript
• Existed since 2015
• Written by Richard Musiol (@neelance)

WebAssembly for Go

• Compile Go packages to WASM
• Also written by Richard Musiol

Server setup

• Copy necessary files

$GOROOT/misc/wasm/wasm_exec.html
$GOROOT/misc/wasm/wasm_exec.js

• Use correct content type

var contentTypeSetter = func(h http.Handler) http.Handler {
    return http.HandlerFunc(func(resp http.ResponseWriter, req *http.Request) {
        if strings.HasSuffix(req.URL.Path, ".wasm") {
            resp.Header().Set("content-type", "application/wasm")
        }
        h.ServeHTTP(resp, req)
    })
}

Go WASM examples

Future

• Go WASM frameworks
• Package-level caching
• Native Browser APIs
• Threading, Garbage Collection (?)
• Continual improvements

We've learned

• To use WebAssembly with Go
• What's possible with WASM today
• What we can look forward to

Further reading

• https://developer.mozilla.org/en-US/docs/WebAssembly
• https://blog.scottlogic.com/2018/07/20/wasm-future.html
• Join the Gophers Slack #webassembly channel

Thanks to

• Richard Musiol (@neelance)
• Pivotal
• London Go meetup organizers

Questions?

Thank you