[boost] Re: [regex] any interest in finite automata-based regex engine?

From: Vladimir Prus (ghost_at_[hidden])
Date: 2004-10-25 05:48:17

Vladimir Pozdyayev wrote:

> Hello.
> 
> Are there any plans to add finite automata-based subengine to the
> regex library? If there are, I can submit the algorithm/implementation
> of a modified nondeterministic FA which takes care of
>    * greedy and lazy quantifiers,
>    * eagerness of the alternation operator,
>    * non-longest matches (`best' in the Perl-ish sense with respect to
>      greediness/laziness/eagerness),
>    * substring capturing.
> All these features being included, the time cost of a match is
> O(N(E+C)L), where N is the number of states, E is the average
> epsilon-closure size per state, C is the number of capturing
> parentheses, and L is the input length. 

Interesting. Is the algorithm from some published paper that you could
link/post? Or do you have a formal description?

- Volodya