[rescue] Re: Ultra 10

[Patrick Giagnocavo]

>Robert Novak wrote:
>
>> Main system uses U5/U10 type memory. Nuff sed.
>
>
>What do you mean "nuff sed"? I've never had one of these before. Is this
>a good or bad thing?

Well, it is all very complicated.  You see, there was the "original" sed,
which was AT&T licensed code.  Then RMS (Stallman) came out with GNU sed,
though I think this was well after a BSDish sed sometime around 3BSD.

As you know, the pattern matching or "regex" functionality of sed uses a
neat little bit of CS quackery called "finite automata" - you can read more
about this in the red dragon book, I think.  There are / were two types :
NFA and DFA.  NFA=nondeterministic finite automata, DFA = deterministic.
Most "POSIX-ized" implementations use DFA, I think; or maybe it is more
that BSDers use NFA and SYS-V'ers use DFA.

Now, apparently, the NUFF style is a little different.  This is still a
subject of a lot of CS theses, and the optimizations are not yet fully
explored.

My belief is that NUFF = Non-Uniform Full Flush.  This sounds more
complicated than it is - basically you do your matching until a fitness
function determines that you have "enough" and then you do a full flush of
the output...

Hope this helps.


Cordially
--
Patrick Giagnocavo
patrick at zill.net
Web Hosting:  http://www.zill.net/