I don't know if I hallucinated this but maybe someone recognises it:
I'm sure I once (~20 years ago) saw an arbitrary precision real number library for C or C++ that worked by picking some fixed precision and worked until it produced a result at the required precision, or, if it convinced itself it couldn't achieve that precision, did some kind of backtracking so it could redo the computation at a higher fixed precision. Somewhat analogously to how transactional memory works - and I think under the hood there may have been some unusual memory model.
@dpiponi On a multicore computer, it might make sense to start multiple fixed-point computations in parallel, and then kill them as they fail or as soon as one of them produces a result.
@fanf@dpiponi also spigot doesn't match any of the rest of that description! Exact real calculator, yes; but it doesn't come in library form¹, mostly doesn't work² by retrying calculations from scratch in higher and higher precision, and certainly doesn't do anything resembling transactional memory.
¹ unless you count the not-quite-published Python wrapper module
² a few number-generating classes do redo from start, but it's always a last-ditch fallback when I couldn't think of a better way
Add comment