Merge pull request #38 from Bubbler-4/explored-fix

Hi thanks a lot for your interest, and for taking the time to send a fix (which I should've noticed and fixed ages ago).

Given that you intend to take some time to bring improvements to the crate, you might be interested in reading chap 4 of my phd thesis (https://dial.uclouvain.be/pr/boreal/object/boreal:266171). This is the chapter where I discussed design and peformance consideration, so you might use it as a bit of an additional documentation to get the rationale behind some implementation decisions.

Please note that the introduction of dominance caching (that we published later with V. Coppé and P. Schaus) led to some design changes wrt what is explained in my thesis. This subproblem dominance caching is probably the reason you see so many critical sections hit (https://arxiv.org/pdf/2211.13118).

Anyways,
Thank you again for your contribution, I hope that these additional bits of info will be useful to you. And most of all, I hope that you'll enjoy working w/ ddo !

ddo/src/abstraction/solver.rs

@@ -93,5 +93,5 @@ pub trait Solver {
     }
 
     /// Returns the number of nodes that have been explored during the search.
-    fn explored() -> usize;
+    fn explored(&self) -> usize;
 }