readme.md

go-elrpc : EPC (RPC Stack for Emacs Lisp) for Go

EPC is an RPC stack for Emacs Lisp and elrpc is an implementation of EPC in Go. Using elrpc, you can develop an emacs extension in Go.

• EPC at github

Sample Code

Go code (server process)

This sample code defines a simple echo method. Emacs starts this code as a child process.

echo.go

package main

import (
	"fmt"
	"github.com/kiwanami/go-elrpc"
)

func main() {
	// construct epc server
	s, err := elrpc.StartServerWithPort(nil, 0)
	if err != nil {
		fmt.Printf(err.Error())
		return
	}

	// register echo method
	s.RegisterMethod(elrpc.MakeMethod("echo", func(arg interface{}) interface{} {
		return arg
	}, "any", "return the given value"))

	// wait for client's connections
	s.Wait()
}

Emacs Lisp code (client process)

This elisp code starts a child process and calls the echo method.

echo-client.el

(require 'epc)

;; eval each s-exp one by one with `eval-last-sexp'

(setq epc (epc:start-epc (expand-file-name "./echo") nil))

(deferred:$
  (epc:call-deferred epc 'echo '(10))
  (deferred:nextc it 
    (lambda (x) (message "Return : %S" x))))

(deferred:$
  (epc:call-deferred epc 'echo '("Hello go-elrpc"))
  (deferred:nextc it 
    (lambda (x) (message "Return : %S" x))))

(epc:stop-epc epc)

Go code (client process)

You can also connect between Go processes.

echo-client.go

package main

import (
	"fmt"
	"github.com/kiwanami/go-elrpc"
)

func main() {
	sv, err := elrpc.StartProcess([]string{"./echo"}, nil)
	if err != nil {
		fmt.Println("Could not start epc process")
		return
	}
	defer sv.Stop()

	ret, err := sv.Call("echo", 1)
	if err != nil {
		fmt.Printf("Error: %v\n", err.Error())
		return
	}

	fmt.Printf("Echo return: %v\n", ret)
}

Here is the result.

$ go run echo-client.go
Echo return: 1

Installation

$ go get github.com/kiwanami/go-elrpc

License

go-elrpc is licensed under MIT.

---

(C) 2017 SAKURAI Masashi. m.sakurai at kiwanami.net