Powerset construction in C#

The terminology is a little confusing. It's better to call the NFA to DFA algorithm the "subset construction". The power set is a term which is used to denote the set of all subsets of a set. The states of a DFA are not all the possible subsets of the NFA; just those subsets which are generated by epsilon-closures on the state transitions. I.e. the set of DFA states consists of a subset of the power set of the NFA states.

Believe it or not, I implemented powerset() as a joke in Gosu years ago:<p><pre><code> var set : java.util.Set&lt;String&gt; = {&quot;a&quot;, &quot;b&quot;, &quot;c&quot;} print( set.powerSet() ) </code></pre> prints<p><pre><code> [[], [b], [c], [b, c, a], [a], [b, c], [a, c], [b, a]] </code></pre> You can try it here (until the Heroku dyno goes down):<p><pre><code> http:&#x2F;&#x2F;gosu-lang.github.io&#x2F;play.html</code></pre>