rudolph9/README.md

## README.md

      
    Raw
  

              README.md
            
          
    Cue Web Assembly

Followed tutorial here: https://github.com/golang/go/wiki/WebAssembly
Setup


install compatible version of golang. Test with go1.12.8
get cue: go get -u cuelang.org/go/cue NOTE: this installs the packages files, not the cmd
get the wasm exec_file cp "$(go env GOROOT)/misc/wasm/wasm_exec.js

Build


Build the wasm: GOARCH=wasm GOOS=js go build -o lib.wasm main.go

Serve files


install goexec if needed (or serve the files some other way): go get -u github.com/shurcooL/goexec


Serve files: goexec 'http.ListenAndServe(":8080", http.FileServer(http.Dir(".")))'


## index.html
<!DOCTYPE html>
<!--
Copyright 2018 The Go Authors. All rights reserved.
Use of this source code is governed by a BSD-style
license that can be found in the LICENSE file.
-->
<html>
  <head>
    <meta charset="utf-8" />
    <title>Go wasm</title>
  </head>

  <body>
    <script src="wasm_exec.js"></script>

    <script>
      if (!WebAssembly.instantiateStreaming) {
        // polyfill
        WebAssembly.instantiateStreaming = async (resp, importObject) => {
          const source = await (await resp).arrayBuffer();
          return await WebAssembly.instantiate(source, importObject);
        };
      }

      const go = new Go();

      let mod, inst;

      WebAssembly.instantiateStreaming(fetch("lib.wasm"), go.importObject).then(
        result => {
          mod = result.module;
          inst = result.instance;
          document.getElementById("runButton").disabled = false;
        }
      );

      async function run() {
        await go.run(inst);
        inst = await WebAssembly.instantiate(mod, go.importObject); // reset instance
      }
    </script>

    <button onClick="run();" id="runButton" disabled>Run</button>
  </body>
</html>

## main.go
package main

import (
	"fmt"
	"math/big"

	"cuelang.org/go/cue"
)

func main() {
	const config = `
TimeSeries: {
  "2019-09-01T07:00:00Z": 36
}
TimeSeries: {
  "2019-09-01T07:10:59Z": 200
}
`
	var r cue.Runtime

	instance, err := r.Compile("test", config)
	if err != nil {
		fmt.Println(err)
	}

	var bigInt big.Int
	instance.Lookup("TimeSeries").Lookup("2019-09-01T07:10:59Z").Int(&bigInt)
	fmt.Println(bigInt.String())
}

## wasm_exec.js
// get this file by running `cp "$(go env GOROOT)/misc/wasm/wasm_exec.js"`
	<!DOCTYPE html>
	<!--
	Copyright 2018 The Go Authors. All rights reserved.
	Use of this source code is governed by a BSD-style
	license that can be found in the LICENSE file.
	-->
	<html>
	<head>
	<meta charset="utf-8" />
	<title>Go wasm</title>
	</head>

	<body>
	<script src="wasm_exec.js"></script>

	<script>
	if (!WebAssembly.instantiateStreaming) {
	// polyfill
	WebAssembly.instantiateStreaming = async (resp, importObject) => {
	const source = await (await resp).arrayBuffer();
	return await WebAssembly.instantiate(source, importObject);
	};
	}

	const go = new Go();

	let mod, inst;

	WebAssembly.instantiateStreaming(fetch("lib.wasm"), go.importObject).then(
	result => {
	mod = result.module;
	inst = result.instance;
	document.getElementById("runButton").disabled = false;
	}
	);

	async function run() {
	await go.run(inst);
	inst = await WebAssembly.instantiate(mod, go.importObject); // reset instance
	}
	</script>

	<button onClick="run();" id="runButton" disabled>Run</button>
	</body>
	</html>
	package main

	import (
	"fmt"
	"math/big"

	"cuelang.org/go/cue"
	)

	func main() {
	const config = `
	TimeSeries: {
	"2019-09-01T07:00:00Z": 36
	}
	TimeSeries: {
	"2019-09-01T07:10:59Z": 200
	}
	`
	var r cue.Runtime

	instance, err := r.Compile("test", config)
	if err != nil {
	fmt.Println(err)
	}

	var bigInt big.Int
	instance.Lookup("TimeSeries").Lookup("2019-09-01T07:10:59Z").Int(&bigInt)
	fmt.Println(bigInt.String())
	}