Official Go implementation of the Ethereum protocol
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go-ethereum/vendor/gopkg.in/olebedev/go-duktape.v3/README.md

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# Duktape bindings for Go(Golang)
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[Duktape](http://duktape.org/index.html) is a thin, embeddable javascript engine.
Most of the [api](http://duktape.org/api.html) is implemented.
The exceptions are listed [here](https://github.com/olebedev/go-duktape/blob/master/api.go#L1566).
### Usage
The package is fully go-getable, no need to install any external C libraries.
So, just type `go get gopkg.in/olebedev/go-duktape.v3` to install.
```go
package main
import "fmt"
import "gopkg.in/olebedev/go-duktape.v3"
func main() {
ctx := duktape.New()
ctx.PevalString(`2 + 3`)
result := ctx.GetNumber(-1)
ctx.Pop()
fmt.Println("result is:", result)
// To prevent memory leaks, don't forget to clean up after
// yourself when you're done using a context.
ctx.DestroyHeap()
}
```
### Go specific notes
Bindings between Go and Javascript contexts are not fully functional.
However, binding a Go function to the Javascript context is available:
```go
package main
import "fmt"
import "gopkg.in/olebedev/go-duktape.v3"
func main() {
ctx := duktape.New()
ctx.PushGlobalGoFunction("log", func(c *duktape.Context) int {
fmt.Println(c.SafeToString(-1))
return 0
})
ctx.PevalString(`log('Go lang Go!')`)
}
```
then run it.
```bash
$ go run *.go
Go lang Go!
$
```
### Timers
There is a method to inject timers to the global scope:
```go
package main
import "fmt"
import "gopkg.in/olebedev/go-duktape.v3"
func main() {
ctx := duktape.New()
// Let's inject `setTimeout`, `setInterval`, `clearTimeout`,
// `clearInterval` into global scope.
ctx.PushTimers()
ch := make(chan string)
ctx.PushGlobalGoFunction("second", func(_ *Context) int {
ch <- "second step"
return 0
})
ctx.PevalString(`
setTimeout(second, 0);
print('first step');
`)
fmt.Println(<-ch)
}
```
then run it
```bash
$ go run *.go
first step
second step
$
```
Also you can `FlushTimers()`.
### Command line tool
Install `go get gopkg.in/olebedev/go-duktape.v3/...`.
Execute file.js: `$GOPATH/bin/go-duk file.js`.
### Benchmarks
| prog | time |
| ------------|-------|
|[otto](https://github.com/robertkrimen/otto)|200.13s|
|[anko](https://github.com/mattn/anko)|231.19s|
|[agora](https://github.com/PuerkitoBio/agora/)|149.33s|
|[GopherLua](https://github.com/yuin/gopher-lua/)|8.39s|
|**go-duktape**|**9.80s**|
More details are [here](https://github.com/olebedev/go-duktape/wiki/Benchmarks).
### Status
The package is not fully tested, so be careful.
### Contribution
Pull requests are welcome! Also, if you want to discuss something send a pull request with proposal and changes.
__Convention:__ fork the repository and make changes on your fork in a feature branch.