I think thats exactly what indirectly happened. This guy didnt optimize the parser. Someone else did -- years ago. That work was pulled into the LLM and made it look like magic.
Note that it's not a particularly optimized algorithm: recursive descent + specialized subparser for expressions is simply the standard way to write parsers by hand. It's ANTLR which is super flexible but also dog slow.
Note that it's not a particularly optimized algorithm: recursive descent + specialized subparser for expressions is simply the standard way to write parsers by hand. It's ANTLR which is super flexible but also dog slow.