def reset_indent(TokenClass):
    """Reset the indentation levels."""
    def callback(lexer, match, context):
        text = match.group()
        context.indent_stack = []
        context.indent = -1
        context.next_indent = 0
        context.block_scalar_indent = None
        yield match.start(), TokenClass, text
        context.pos = match.end()
    return callback