Files
wazero/imports/assemblyscript/example/assemblyscript.go
Crypt Keeper 329ccca6b1 Switches from gofmt to gofumpt (#848)
This switches to gofumpt and applies changes, as I've noticed working
in dapr (who uses this) that it finds some things that are annoying,
such as inconsistent block formatting in test tables.

Signed-off-by: Adrian Cole <adrian@tetrate.io>
2022-11-09 05:48:24 +01:00

80 lines
2.2 KiB
Go

package main
import (
"context"
_ "embed"
"fmt"
"log"
"os"
"strconv"
"github.com/tetratelabs/wazero"
"github.com/tetratelabs/wazero/imports/assemblyscript"
)
// asWasm compiled using `npm install && npm run build`
//
//go:embed testdata/index.wasm
var asWasm []byte
// main shows how to interact with a WebAssembly function that was compiled
// from AssemblyScript
//
// See README.md for a full description.
func main() {
// Choose the context to use for function calls.
ctx := context.Background()
// Create a new WebAssembly Runtime.
r := wazero.NewRuntime(ctx)
defer r.Close(ctx) // This closes everything this Runtime created.
// Instantiate a module implementing functions used by AssemblyScript.
// Thrown errors will be logged to os.Stderr
_, err := assemblyscript.Instantiate(ctx, r)
if err != nil {
log.Panicln(err)
}
// Compile the WebAssembly module using the default configuration.
code, err := r.CompileModule(ctx, asWasm)
if err != nil {
log.Panicln(err)
}
// Instantiate a WebAssembly module that imports the "abort" and "trace"
// functions defined by assemblyscript.Instantiate and exports functions
// we'll use in this example.
mod, err := r.InstantiateModule(ctx, code, wazero.NewModuleConfig().
// Override the default module config that discards stdout and stderr.
WithStdout(os.Stdout).WithStderr(os.Stderr))
if err != nil {
log.Panicln(err)
}
// Get references to WebAssembly functions we'll use in this example.
helloWorld := mod.ExportedFunction("hello_world")
goodbyeWorld := mod.ExportedFunction("goodbye_world")
// Let's use the argument to this main function in Wasm.
numStr := os.Args[1]
num, err := strconv.Atoi(numStr)
if err != nil {
log.Panicln(err)
}
// Call hello_world, which returns the input value incremented by 3.
// While this calls trace(), our configuration didn't enable it.
results, err := helloWorld.Call(ctx, uint64(num))
if err != nil {
log.Panicln(err)
}
fmt.Printf("hello_world returned: %v", results[0])
// Call goodbye_world, which aborts with an error.
// assemblyscript.Instantiate was configured above to abort to stderr.
if _, err = goodbyeWorld.Call(ctx); err == nil {
log.Panicln("goodbye_world did not fail")
}
}