gistfile1.txt

/*
Command er-release prints the PRs merged since the last release

These should be added to CHANGELOG.md with an appropriate version.
*/
package main

import (
	"flag"
	"fmt"
	"log"
	"os/exec"
	"strings"
)

var (
	from = flag.String("from", "", "git tree-ish of the previous release; defaults to the last change of CHANGELOG.md")
	to   = flag.String("to", "HEAD", "git tree-ish of the current release")
)

func main() {
	flag.Parse()

	if *from == "" {
		if err := setLastChangelog(); err != nil {
			log.Fatal(err)
		}
	}

	fmt.Println(*from, *to)

	out, err := git("log", *from+".."+*to)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(string(out))
}

func setLastChangelog() error {
	out, err := git("log", "--format=format:%H", "-1", "CHANGELOG.md")
	if err != nil {
		return err
	}
	*from = strings.TrimSpace(string(out))
	return nil
}

func git(args ...string) ([]byte, error) {
	return exec.Command("git", args...).Output()
}

func split(s string) []string) {
	re := regexp.MustCompile("^commit ")
	
}