[ato]

Thanks. Yeah, fast anything code tends to be not very pretty to look at and I'm not a very experienced lisper. But fortunately in most real-world programs the part that is performance critical tends to be very small compared to the rest of the program.

[jwr]

Oh, I didn't mean it as a criticism -- I'm afraid it has to be that way. My Common Lisp code that has been optimized looks similar (sprinkled with type declarations in various places).