Why no & operation?

[riyueniao]

Why there isn't an operation like the following code.

// for same input, `p & q` succeeds if `p` succeeds and `q` succeeds. 
def & [U >: T](q: => Parser[U]): Parser[U] = ???

[peteraldous]

I'm not sure, but it isn't clear to me which result should be returned. The type signature suggests that q's result would be returned, but that seems like an arbitrary choice that would surprise some users.