'Process indentation spaces in a plain scalar.'

def parse_plain_scalar_indent(token_class):

    def callback(lexer, match, context):
        text = match.group()
        if (len(text) <= context.indent):
            context.stack.pop()
            context.stack.pop()
            return
        if text:
            (yield (match.start(), token_class, text))
            context.pos = match.end()
    return callback
