Oh, wow! Thanks for the correction. I had somehow missed that. I'm working on a rust parser of Elixir myself, and using LALRPOP for it. But looks like I'll have to check out pest, too. LALRPOP has the advantage that it takes a BNF grammar, which the Elixir parser in erlang includes, so it's a somewhat straightforward translation. Not too sure how similar it is to a PEG grammar that pest takes.