Top Down Operator Precedence

And here's a truly nifty application of it for parsing Python: http://effbot.org/zone/simple-top-down-parsing.htm .

Funny how these things go in cycles: parser generators were all the rage for a few decades, and now people are rediscovering the pleasures and strengths of top-down recursive parsers. (E.g., in the new clang compiler that's part of the LLVM project.)