What are the benefits of applicative parsing over monadic parsing?

Question

There seems to be a consensus that you should use Parsec as an applicative rather than a monad. What are the benefits of applicative parsing over monadic parsing?

Answer 1

If a parser is purely applicative, it is possible to analyse its structure and "optimise" it before running it. If a parser is monadic, it's basically a Turing-complete program, and performing almost any interesting analysis of it is equivalent to solving the halting problem (i.e., impossible).

Oh, and yes, there's a stylistic difference too...