The problem here was wanting to parse a large file at all. You need to be able to do a) online parsing (so you don't need to read the whole file into memory fi

The problem here was wanting to parse a large file at all. You need to be able to do a) online parsing (so you don't need to read the whole file into memory first), b) stream parse (so you don't need to build a parsed representation of the whole thing before you can do anything).