explicitly represented in an fltype_t struct, and symbolic
types are hash-consed. a lot of code is smaller and simpler
as a result. this should allow more features in less space
(both code and data) going forward.
changing \DDD and \x escape sequences to read bytes instead of
characters
re-fixing uint64 cast bug
adding Paul Hsieh's hash function, to be evaluated later
JeffBezanson