| 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/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/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/analysisinternal/typeindex | Package typeindex defines an analyzer that provides a golang.org/x/tools/internal/typesinternal/typeindex.Index. |
| golang.org/x/tools/internal/typesinternal/typeindex | Package typeindex provides an Index of type information for a package, allowing efficient lookup of, say, whether a given symbol is referenced and, if so, where from; or of the cursor.Cursor for the declaration of a particular types.Object symbol. |