Viewing profile — d66

It wouldn't be idiomatic Uxntal but there's a relatively simple modification where load/store is from RAM space but jump/pc is from ROM space. For a subset of existing programs it …

That's a fair point. A few of us have been discussing a modified Varvara spec that limits the system to a smaller amount of memory (e.g. 32k, 16k, or 8k). I think with a spec like …

I'm not sure that's true. I have an eZ80-based emulator for the AgonLight2 that is already running well enough to run some real (console-based) ROMs: https://git.phial.org/d6/uxn-e…

There's no requirement that stacks grow upwards in Varvara. If your stacks grew downwards then you could use LE instructions to operate on 16-bit values on the stack. You'd still n…

yes, that is the actual construction: the disjunction data type only supports a lhs and rhs, so that is the only possible way to represent it. i wrote it the way i did for clarity …

negation (~α): strings not matched by α difference (α - β): strings matched by α but not β intersection (α & β): strings matched by α and β exclusive-or (α ^ β): strings matched by…

you're right. inclusion/intersection/etc. aren't actually computed via DFA but instead are computed directly on the regular expression representation itself. and large disjunctions…

the library uses a fairly simple data representation where x{m,n} is compiled using conjunction and disjunction. so x{1,4} ends up being represented as x|xx|xxx|xxxx. this simplifi…

interesting! what would [ab]* be? for computing an ordinal number the only real difficulty is how to handle kleene star: given ord(X) how do we calculate ord(X*)? but as you probab…

expressions like (...){1,256} are very heavyweight and the scala JS code ends up timing out or crashing the browser. if you replace that with (...)+ then it seems to work (at least…

normally you would use an ordinal number [1] to label individual elements of an infinite set while using a cardinal number [2] to measure the size of the set. i believe the cardina…

the page actually does give these. for α := [a-z]{2,4} the page gives |α| = 475228. however, as others have pointed out any non-trivial use of the kleene star means the result will…