Christopher Kings-Lynne <chriskl@familyhealth.com.au> writes:
>> Parsing is a whole nother ball of wax besides lexing.
> Forgive my lameness, but I've never truly figured out where parsing ends
> and lexing begins. Anyone care to illuminate me on the difference?
The theoretical answer is that you can do lexing with a finite-state
machine, but parsing generally requires a stack, because it supports
nested constructs. Lexers don't have any way to describe nested
constructs --- a series of tokens is the only level of abstraction there
is.
The practical answer is that you do one with flex and the other with
bison ;-). If you can do it with flex, and not cheat by implementing
your own state stack, it's lexing.
regards, tom lane
