| errors | Package errors implements functions to manipulate errors. |
| golang.org/x/text/encoding | Package encoding defines an interface for character encodings, such as Shift JIS and Windows 1252, that can convert to and from UTF-8. |
| golang.org/x/text/encoding/charmap | Package charmap provides simple character encodings such as IBM Code Page 437 and Windows 1252. |
| golang.org/x/text/encoding/internal/identifier | Package identifier defines the contract between implementations of Encoding and Index by defining identifiers that uniquely identify standardized coded character sets (CCS) and character encoding schemes (CES), which we will together refer to as encodings, for which Encoding implementations provide converters to and from UTF-8. |
| golang.org/x/text/encoding/japanese | Package japanese provides Japanese encodings such as EUC-JP and Shift JIS. |
| golang.org/x/text/encoding/korean | Package korean provides Korean encodings such as EUC-KR. |
| golang.org/x/text/encoding/simplifiedchinese | Package simplifiedchinese provides Simplified Chinese encodings such as GBK. |
| golang.org/x/text/encoding/traditionalchinese | Package traditionalchinese provides Traditional Chinese encodings such as Big5. |
| golang.org/x/text/encoding/unicode | Package unicode provides Unicode encodings such as UTF-16. |
| golang.org/x/text/language | Package language implements BCP 47 language tags and related functionality. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |