[haberman]

> Packrat parsers are notably faster than recursive descent parsers

I think this needs to be qualified. I don't think a packrat parser is going to beat a deterministic top-down parser. Maybe the packrat parser will win if the recursive descent parser is backtracking.

[morelisp]

True - the performance of a top-down parser is going to depend on if/how often it backtracks and how much lookahead it requires. But this requires control over your grammar which you might not have i.e. you are parsing a standardized programming language. Practically speaking, unless you want two separate parsing engines in your IDE, that Lisps are actually LL(1) and Python and Java are "almost LL(1)" doesn't get you closer to parsing C++.

Packrat parsers are equivalent to arbitrary lookahead in either LL or LR grammars.

[specialist]

u/morelisp may have meant faster to develop, not runtime performance.