| 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. |
| go/ast | Package ast declares the types used to represent syntax trees for Go packages. |
| go/constant | Package constant implements Values representing untyped Go constants and their corresponding operations. |
| go/format | Package format implements standard formatting of Go source. |
| go/token | Package token defines constants representing the lexical tokens of the Go programming language and basic operations on tokens (printing, predicates). |
| go/types | Package types declares the data types and implements the algorithms for type-checking of Go packages. |
| golang.org/x/mobile/internal/importers | The importers package uses go/ast to analyze Go packages or Go files and collect references to types whose package has a package prefix. |
| golang.org/x/mobile/internal/importers/java | The java package takes the result of an AST traversal by the importers package and queries the java command for the type information for the referenced Java classes and interfaces. |
| golang.org/x/mobile/internal/importers/objc | The objc package takes the result of an AST traversal by the importers package and uses the clang command to dump the type information for the referenced ObjC classes and protocols. |
| html | Package html provides functions for escaping and unescaping HTML text. |
| io | Package io provides basic interfaces to I/O primitives. |
| log | Package log implements a simple logging package. |
| math | Package math provides basic constants and mathematical functions. |
| path | Package path implements utility routines for manipulating slash-separated paths. |
| reflect | Package reflect implements run-time reflection, allowing a program to manipulate objects with arbitrary types. |
| regexp | Package regexp implements regular expression search. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| unicode | Package unicode provides data and functions to test some properties of Unicode code points. |
| unicode/utf8 | Package utf8 implements functions and constants to support text encoded in UTF-8. |