5 ms·

But it's very much not non-deterministic. It's a deterministic choice. You can give it an exact semantics.

• zozbot234 4y ago
  How? The slide deck calls it a "lenient" evaluation order, and doesn't really say how to make an explicit choice of what cases should be tried first. So it seems to have all the same problems as naïve Prolog.
  • disconcision 4y ago
    exact semantics are given here: https://simon.peytonjones.org/assets/pdfs/verse-conf.pdf https://simon.peytonjones.org/assets/pdfs/verse-conf.pdf. runtime efficiency isn't specifically addressed afaict
• cryptonector 4y ago
  Correct, but "non-determinism" is a misnomer used in programming language theory to refer to generators and pervasive backtracking. Prolog, Icon, jq, etc. -- all fully deterministic, but known as non-deterministic owing to the pervasive generators and backtracking.
  • imtringued 4y ago
    It is not a misnomer. You can use generators and backtracking to simulate non determinism. That means the simulator plus non deterministic algorithm are deterministic but the algorithm is not.
    • cryptonector 4y ago
      The idea in Prolog and such is that you write "goal-seeking code" and it "magically" obtains the correct answer by brute force but without the brute force being syntactically/lexically apparent. But it's still brute force. It's a catchy name, but it's not accurate. It might be more accurate if "simulation" were part of the name.
      • FullyFunctional 4y ago
        As presented in the slides it's obvious that it's a generator-paradigm, thus like Icon etc. It's really just a way of making iterators very fundamental in the language. It's deterministic and you are assume to understand that. The "PROLOG style goal searching" is probably less relevant here.