mymoomin · HackerTrans

anno scorsodiscuss

You have a typo in [1]. It should read "A countable union of (finite or) countable sets is countable."

anno scorsodiscuss

A "branch" here is a conditional jump. This has the issues the article mentions, which branchless programming avoids:

    Again, there is no branching - the instruction pointer isn't manipulated, there's no branch prediction involved, no instruction cache to invalidate, no nothing.

This has nothing to do with whether the behaviour of some instruction depends on its arguments. Looking at the Microsoft compiler output from the article, the iadd (signed add) instruction will get different results depending on its arguments, and the movc (conditional move) will store different values depending on its arguments, but after each the instruction pointer will just move onto the next instruction, so there are no branches.

mymoomin

2 anni fadiscuss

The article is right to say that set theory can serve as a foundation for almost all other mathematics, and you're also right to say that no reasonably-complex consistent system of axioms can be complete. The resolution to this is that if you ground something (let's say topology) in e.g. ZFC (the most commonly used system of axioms for set theory) then incompleteness in ZFC maps to incompleteness in topology. Here's an example https://en.wikipedia.org/wiki/Moore_space_(topology)#Normal_... .

There are other foundations, some of which are based on things other than set theory (category theory, type theory), but they're usually equivalent to ZFC ± a few axioms, because you can embed those other foundations in some kind of set theory, and embed set theory in the other foundations.

mymoomin

2 anni fadiscuss

I don't see how the article is pretending anything. They had platform issues with C++ (portability and usability on the platforms they supported), and switching to Rust fixed those issues but gave them a different set of platform issues (they could no longer support Cygwin).

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