Program outputting a program that outputs itself

self-printer-printer.go

package main

import (
	"fmt"
	"regexp"
)

func main() {

	in := `
		package main
		import "fmt"
		func main() {
			s := "$"
			fmt.Printf(s, @)
		}
	`
	re, _ := regexp.Compile("\n|\t|\"|\\$|@|.")
	
	args := re.ReplaceAllStringFunc(in, func (s string) string {
		switch s {
			case "\n":	return "10, "
			case "\t":	return "9, "
			case "\"":	return "34, "
			case "$":	return "s, "
			case "@":	return ""
			default:	return ""
		}
	})
	
	fmts := re.ReplaceAllStringFunc(in, func (s string) string {
		switch s {
			case "\n":	return "%c"
			case "\t":	return "%c"
			case "\"":	return "%c"
			case "$":	return "%s"
			case "@":	return args
			default:	return s
		}
	})

	code := re.ReplaceAllStringFunc(in, func (s string) string {
		switch s {
			case "$":	return fmts
			case "@":	return args
			default:	return s
		}
	})

	fmt.Print(code)
}