switch {
						case r >= 'a' && r <= 'z':
							return r
						case r >= 'A' && r <= 'Z':
							return r
						case r >= '0' && r <= '9':
							return r
						case strings.ContainsAny(string(r), "+=-_()!@."):
							return r
						default:
							return '_'
						}
					}, file)
				}
				err := data.files(func(name string, data []byte) {