main.go

package main

import (
	"bytes"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
)

func main() {
	custom, err := ioutil.ReadFile("_gen.go")
	if err != nil {
		log.Println(err)
	}
	err = os.Mkdir("._gen", 0777)
	if err != nil {
		log.Println(err)
	}
	err = ioutil.WriteFile("._gen/gen_custom.go", custom, 0644)
	if err != nil {
		log.Fatal(err)
	}
	err = ioutil.WriteFile("._gen/gen.go", []byte(gentemplate), 0644)
	if err != nil {
		log.Fatal(err)
	}
	cmd := exec.Command("go", "build", "-o", "._gen/gen", "._gen/gen.go", "._gen/gen_custom.go")
	var out bytes.Buffer
	cmd.Stderr = &out
	err = cmd.Run()
	if err != nil {
		log.Println(out.String())
		log.Fatal(err)
	}
	cmd = exec.Command("._gen/gen", os.Args...)
	cmd.Stderr = &out
	err = cmd.Run()
	if err != nil {
		log.Println(out.String())
		log.Fatal(err)
	}
	err = os.RemoveAll("._gen")
	if err != nil {
		log.Println(err)
	}
}

const gentemplate = `package main

import (
	"github.com/clipperhouse/typewriter"
	_ "github.com/clipperhouse/typewriters/genwriter"
	_ "github.com/clipperhouse/typewriters/container"
)

func main() {
	app, err := typewriter.NewApp("+gen")
	if err != nil {
		panic(err)
	}

	app.WriteAll()
}
`