// Len returns the number of bytes of the unread portion of the
// slice.
func (r *Reader) Len() int {
	if r.i >= int64(len(r.s)) {
		return 0
	}
	return int(int64(len(r.s)) - r.i)
}

// Size returns the original length of the underlying byte slice.
// Size is the number of bytes available for reading via [Reader.ReadAt].
// The result is unaffected by any method calls except [Reader.Reset].

			if err != nil {
				return err
			}
			perm = info.Mode() & os.ModePerm
		}

		// Always copy directories (don't symlink them).
		// If we add a file in the overlay, we don't want to add it in the original.
		if info.IsDir() {
			return os.MkdirAll(dstPath, perm|0200)
		}

		// If the OS supports symlinks, use them instead of copying bytes.
		if err := os.Symlink(srcPath, dstPath); err == nil {
			return nil
		}

// The underlying scanner elides all spaces except newline, so the input looks like a stream of
// Tokens; original spacing is lost but we don't need it.
type TokenReader interface {
	// Next returns the next token.
	Next() ScanToken
	// The following methods all refer to the most recent token returned by Next.
	// Text returns the original string representation of the token.
	Text() string
	// File reports the source file name of the token.