Refactor from P' Roof Go Presentation

roof.go

package main

import (
	"fmt"
	"log"
	"os"
	"time"
)

func export(i int) {
	filename := fmt.Sprintf("%d.test.txt", i)
	fmt.Println("writing:", filename)

	f, err := os.Create(filename)
	if err != nil {
		log.Fatal(err)
	}
	defer f.Close()

	for i := 0; i < 10; i++ {
		fmt.Println(filename, ":", i)
		fmt.Fprintf(f, "%d ", i)
		time.Sleep(time.Millisecond * 100)
	}
}

func main() {
	done := make(chan struct{}, 100)
	for i := 0; i < 100; i++ {
		go func(i int) {
			export(i)
			done <- struct{}{}
		}(i)
	}
	<-done
}