For grammar parser, I used to "play" with Bison which have its pros/cons.
Last week, I noticed on SqLite site that the engine is done with another grammar parser: Lemon
Sounds great after reading the thin documentation.
Do you have some feedback about this parser?
Cannot really see pertinent information on Google and Wikipedia (just a few examples, same tutorials) It doesn't seem very popular. (there is no lemon tag in Stack Overflow [ed: there is now :P])
Interesting find! I haven't actually used it, so the commentary is based on reading the documentation.
The redesign so that the lexical analysis is done separately from the parsing immediately seems to have merit. In particular, it has the potential to simplify operations such as handling multiple or nested source files. The Lex-based yywrap() mechanism is less than ideal. That it avoids all global variables and has careful memory allocation and deallocation control should count in its favour (that it allows the choice of allocator and deallocator greatly helps too - at least for the environments where I work, where memory allocation is always an issue).
The rethinking on how the rules are organized and how the terminals are identified is a good idea.
All in all, it looks like a well thought out redesign of Bison.
It is in the public domain according to the referenced web pages.