Re: StablePtr / StableName ?

Dear Simon, thanks for looking into this.

is StableName in the inner loop?

Yes. This application's inner loop uses a HashMap (StableName Expression) Int for memoization. This is the Tseitin transform: for each node, build a literal. Each node is stable-named. I guess the RTS's hashmap performance comes into play only when pointers are moved (in GC). The application's hashmap cost will dominate, because it's used more often.

You'd have to measure it.

I did. It seems we're good on StableNames, and time goes elsewhere. https://github.com/ekmett/ersatz/issues/30#issuecomment-274775792 - Johannes.