Re: [gnugo-devel] DFA rewrite

[Tanguy URVOY]

Hi,

Inge Wallin wrote:
> This is a good idea, but there is a little problem.
> 
> If you do a profile of the running engine, you can clearly see that
> pattern matching itself takes less than 10% of the run time and
> reading takes almost 90%.  All this reading comes from constraints in
> the pattern, i.e. once a pattern has matched some reading is done to
> see if it really applies.


Global DFA scaning with match sets allows us to precompute 
a lot of constrains like goal testing before reading.
What Did you profile the time spent in goal testing ?


This is true that we can only save 9% of the time in the actual engine, 
but a fast and robust pattern matcher is a key to build robust 
reading algorithms. 
This is worth it and the memory usage can be controlled.


When i worked on the first version of the DFA matcher
there was the same little problem. But owl was not 
yet implemented in gnugo...
This should be tried.

-- 
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Tanguy Urvoy http://www.turvoy.fr.st
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