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77 lines
1.9 KiB
77 lines
1.9 KiB
5 years ago
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# Go
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Wasmtime [is available as a Go
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Module](https://pkg.go.dev/github.com/bytecodealliance/wasmtime-go). This guide
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will go over adding Wasmtime to your project, and some provided examples of what
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can be done with WebAssembly modules.
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Make sure you're using Go 1.12 or later with modules support.
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## Getting started and simple example
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First up you'll want to start a new module:
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```sh
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$ mkdir hello-wasm
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$ cd hello-wasm
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$ go mod init hello-wasm
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```
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Next, copy this example WebAssembly text module into your project. It exports a
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function for calculating the greatest common denominator of two numbers.
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```wat
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{{#include ../examples/gcd.wat}}
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```
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Next, we can write our code in `main.go` which reads this file and runs it:
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```go
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package main
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import (
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"fmt"
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"github.com/bytecodealliance/wasmtime-go"
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)
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func main() {
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store := wasmtime.NewStore(wasmtime.NewEngine())
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module, err := wasmtime.NewModuleFromFile(store, "gcd.wat")
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check(err)
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instance, err := wasmtime.NewInstance(module, []*wasmtime.Extern{})
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check(err)
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gcd := instance.GetExport("gcd").Func()
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val, err := gcd.Call(6, 27)
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check(err)
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fmt.Printf("gcd(6, 27) = %d\n", val.(int32))
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}
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func check(err error) {
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if err != nil {
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panic(err)
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}
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}
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```
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And finally we can build and run it:
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```sh
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$ go run main.go
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gcd(6, 27) = 3
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```
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If this is the output you see, congrats! You've successfully ran your first
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WebAssembly code in Go!
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## More examples and contributing
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The `wasmtime` Go package [lives in its own
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repository](https://github.com/bytecodealliance/wasmtime-go) and has a [number
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of other more advanced
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examples](https://pkg.go.dev/github.com/bytecodealliance/wasmtime-go?tab=doc#pkg-examples)
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as well. Feel free to browse those, but if you find anything missing don't
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hesitate to [open an
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issue](https://github.com/bytecodealliance/wasmtime-go/issues/new) and let us
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know if you have any questions!
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