generate: Add option type to parser

generate/parse.go

@@ -214,12 +214,19 @@ func (this *parser) parseField(doc string) (uint16, Field, error) {
 	name := this.Value()
 	err = this.Next()
 	if err != nil { return 0, Field { }, err }
+	option := false
+	if this.Kind() == TokenOption {
+		option = true
+		err = this.Next()
+		if err != nil { return 0, Field { }, err }
+	}
 	typ, err := this.parseType()
 	if err != nil { return 0, Field { }, err }
 	return uint16(key), Field {
-		Name: name,
-		Doc:  doc,
-		Type: typ,
+		Name:   name,
+		Doc:    doc,
+		Type:   typ,
+		Option: option,
 	}, nil
 }