On 4/12/07, Tim X <timx / nospam.dev.null> wrote:
> "Robert Dober" <robert.dober / gmail.com> writes:
>
<snip>
>
> Guys, I think your possibly mixing up backtracking and backreferences. It is
> backreferences (referencing a earlier match, often to use as part of the
> definition of a latter match) that NFA is not able to do.
No Tim I was not mixing it up, I said that I was not interested in the
backreferencing history.
You see I am just forgetting the basic stuff but Ola and Mental kindly
gave me a refresher.
> both approaches use
> backtracking.
The DFA cannot use backtracking, surely I am missing something *again*!
>The NFA approach is able to parallelise the choices, reducing the
> overheads of backtracking. So, given n different possible paths to follow,
> instead of, in the worst case, trying n-1 paths and having to backtrack after
> each one, you can try all n paths at once. At least, I htink thats what the
> article was saying form a very quick read and from what I can remember from my
> computability course and finite automata (oh so many years ago now!).
For me it is 25 years and for you?
Yeah I understood that in the same way, actually it is quite simple :)
>
> Tim
> --
> tcross (at) rapttech dot com dot au
>
>
Cheers
Robert

-- 
You see things; and you say Why?
But I dream things that never were; and I say Why not?
-- George Bernard Shaw