github would be better for browsing. But the source is only 117k - I'm surprised how much of a barrier a few clicks and a few seconds was for me. (Partly, I expected it to be bigger.) The 21 files total 18832 lines; there's bison, lex, and a bunch of cuda files. Some is structured as doing similar things for similar cases, so not that long. It seems to include a reasonably complete implementation of SQL in the bison etc (and there are two example files of SQL query sequences). I'm impressed.

There are some line comments, but no overviews. :(