I've used ANTLR4 and parser combinators (haskell). I would say ANTLR4 was really fast to get going, but it hides a lot of execution semantics from the user. It

I've used ANTLR4 and parser combinators (haskell). I would say ANTLR4 was really fast to get going, but it hides a lot of execution semantics from the user. It was pretty difficult for me to debug precedence or even figure out when certain rules were being triggered or why (do not have the antlr4 IDE, maybe that helps). On the other hand writing parser combinators is really reaallly easy. In my experience it's almost just as declarative (you build up chunks of your grammar from smaller chunks), and yet you maintain good control over the control flow of your parser - when it backtracks, what errors you report, etc. And since its in the language you are using, debugging uses regular debugging tools, and custom logic is expressed in regular haskell Now ANTLR4 also allows writing predicates in the target language, but how and when they get executed is pretty difficult to figure out Overall, I would say if the thing you need to parse is pretty simple (clearly specced, straightforward grammar) a parser generator could be worth it. But if theres anything more complex (optional semicolons, context-sensitive ignoring whitespace, etc) I would much prefer the comfort and understandability of parser combinators