| bufio | Package bufio implements buffered I/O. It wraps an io.Reader or io.Writer object, creating another object (Reader or Writer) that also implements the interface but provides buffering and some help for textual I/O. |
| compress/flate | Package flate implements the DEFLATE compressed data format, described in RFC 1951. |
| encoding/binary | Package binary implements simple translation between numbers and byte sequences and encoding and decoding of varints. |
| errors | Package errors implements functions to manipulate errors. |
| hash | Package hash provides interfaces for hash functions. |
| hash/crc32 | Package crc32 implements the 32-bit cyclic redundancy check, or CRC-32, checksum. |
| internal/godebug | Package godebug makes the settings in the $GODEBUG environment variable available to other packages. |
| io | Package io provides basic interfaces to I/O primitives. |
| io/fs | Package fs defines basic interfaces to a file system. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| path | Package path implements utility routines for manipulating slash-separated paths. |
| path/filepath | Package filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths. |
| sort | Package sort provides primitives for sorting slices and user-defined collections. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| time | Package time provides functionality for measuring and displaying time. |
| unicode/utf8 | Package utf8 implements functions and constants to support text encoded in UTF-8. |