| 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/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/tools/go/analysis | Package analysis defines the interface between a modular static analysis and an analysis driver program. |
| golang.org/x/tools/go/analysis/passes/inspect | Package inspect defines an Analyzer that provides an AST inspector (golang.org/x/tools/go/ast/inspector.Inspector) for the syntax trees of a package. |
| golang.org/x/tools/go/ast/inspector | Package inspector provides helper functions for traversal over the syntax trees of a package, including node filtering by type, and materialization of the traversal stack. |
| golang.org/x/tools/go/types/typeutil | Package typeutil defines various utilities for types, such as Map, a hash table that maps types.Type to any value. |
| golang.org/x/tools/internal/diff | Package diff computes differences between text files or strings. |
| golang.org/x/tools/internal/refactor/inline | Package inline implements inlining of Go function calls. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |