go/src/cmd/go/internal/modload/search.go

type stdFilter …

const omitStd …

const includeStd …

// matchPackages is like m.MatchPackages, but uses a local variable (rather than
// a global) for tags, can include or exclude packages in the standard library,
// and is restricted to the given list of modules.
func matchPackages(ctx context.Context, m *search.Match, tags map[string]bool, filter stdFilter, modules []module.Version) { … }

// walkFromIndex matches packages in a module using the module index. modroot
// is the module's root directory on disk, index is the modindex.Module for the
// module, and importPathRoot is the module's path prefix.
func walkFromIndex(index *modindex.Module, importPathRoot string, isMatch, treeCanMatch func(string) bool, tags, have map[string]bool, addPkg func(string)) { … }

// MatchInModule identifies the packages matching the given pattern within the
// given module version, which does not need to be in the build list or module
// requirement graph.
//
// If m is the zero module.Version, MatchInModule matches the pattern
// against the standard library (std and cmd) in GOROOT/src.
func MatchInModule(ctx context.Context, pattern string, m module.Version, tags map[string]bool) *search.Match { … }