def get_all_lexers():
    """Return a generator of tuples in the form ``(name, aliases,
    filenames, mimetypes)`` of all know lexers.
    """
    for item in itervalues(LEXERS):
        yield item[1:]
    for lexer in find_plugin_lexers():
        yield lexer.name, lexer.aliases, lexer.filenames, lexer.mimetypes
Return a generator of tuples in the form ``(name, aliases,
    filenames, mimetypes)`` of all know lexers.