Support including chosen comments in generated code

stringer.go

@@ -31,6 +31,17 @@ import (
 	"github.com/pascaldekloe/name"
 )
 
+type arrayFlags []string
+
+func (af arrayFlags) String() string {
+	return strings.Join(af, "")
+}
+
+func (af *arrayFlags) Set(value string) error {
+	*af = append(*af, value)
+	return nil
+}
+
 var (
 	typeNames       = flag.String("type", "", "comma-separated list of type names; must be set")
 	sql             = flag.Bool("sql", false, "if true, the Scanner and Valuer interface will be implemented.")
@@ -42,6 +53,12 @@ var (
 	trimPrefix      = flag.String("trimprefix", "", "transform each item name by removing a prefix. Default: \"\"")
 )
 
+var comments arrayFlags
+
+func init() {
+	flag.Var(&comments, "comment", "comments to include in generated code, can repeat. Default: \"\"")
+}
+
 // Usage is a replacement usage function for the flags package.
 func Usage() {
 	fmt.Fprintf(os.Stderr, "Usage of %s:\n", os.Args[0])
@@ -88,6 +105,7 @@ func main() {
 	// Print the header and package clause.
 	g.Printf("// Code generated by \"enumer %s\"; DO NOT EDIT.\n", strings.Join(os.Args[1:], " "))
 	g.Printf("\n")
+	g.Printf("// %s\n", comments.String())
 	g.Printf("package %s", g.pkg.name)
 	g.Printf("\n")
 	g.Printf("import (\n")