)

type stdFilter int8

const (
	omitStd = stdFilter(iota)
	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) {

//
// If any errors may have caused the set of packages to be incomplete,
// MatchPackages appends those errors to m.Errs.
func (m *Match) MatchPackages() {
	m.Pkgs = []string{}
	if m.IsLocal() {
		m.AddError(fmt.Errorf("internal error: MatchPackages: %s is not a valid package pattern", m.pattern))
		return
	}

	if m.IsLiteral() {
		m.Pkgs = []string{m.pattern}
		return
	}

	CGO, internal/syscall/unix < net/internal/cgotest;


`

// listStdPkgs returns the same list of packages as "go list std".
func listStdPkgs(goroot string) ([]string, error) {
	// Based on cmd/go's matchPackages function.
	var pkgs []string

	src := filepath.Join(goroot, "src") + string(filepath.Separator)
	walkFn := func(path string, d fs.DirEntry, err error) error {
		if err != nil || !d.IsDir() || path == src {

					}
					matchPackages(ctx, m, opts.Tags, omitStd, matchModules)
				} else {
					// Starting with the packages in the main module,
					// enumerate the full list of "all".
					m.Pkgs = ld.computePatternAll()
				}

			case m.Pattern() == "std" || m.Pattern() == "cmd":
				if m.Pkgs == nil {
					m.MatchPackages() // Locate the packages within GOROOT/src.
				}

			return nil, nil, &WildcardInFirstElementError{Pattern: pattern, Query: query}
		}
		match = func(mod module.Version, roots []string, isLocal bool) *search.Match {
			m := search.NewMatch(pattern)
			matchPackages(ctx, m, imports.AnyTags(), omitStd, []module.Version{mod})
			return m
		}
	} else {
		match = func(mod module.Version, roots []string, isLocal bool) *search.Match {
			m := search.NewMatch(pattern)