So, I think the main reasons are - - Lark is already very fast. It's a lot easier to optimize something that takes 3 minutes :) - There is still some Python c

So, I think the main reasons are - - Lark is already very fast. It's a lot easier to optimize something that takes 3 minutes :) - There is still some Python code that is being run. For example, in the tree constructor. That can be solved in future versions. - I'm not yet taking full advantage of Cython. For example, I'm still keeping the lookup map as a dictionary instead of an array. Also I'm still mostly working with CPython objects instead of native objects (like char*).