Parser combinators info

Question

I am using parsing combinators in scala If I have recursive parser:

val uninterestingthings = ".".r

val parser = "(?ui)(regexvalue)".r | (uninterestingthings~>parser)

How can I check how many characters of input my parser consumed?

Answer 1

有一个positioned组合器（引用其文档）“将解析器的结果与其使用的输入的起始位置一起装饰”。