| bytes | Package bytes implements functions for the manipulation of byte slices. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/pkg/errors | Package errors provides simple error handling primitives. |
| regexp | Package regexp implements regular expression search. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| text/scanner | Package scanner provides a scanner and tokenizer for UTF-8-encoded text. |
| unicode | Package unicode provides data and functions to test some properties of Unicode code points. |