From reading git history I see Lua switched from calling out to C random/srandom or rand/srand (depending on posix) to xorshift128+ and then to xoshiro256**. That’s a nice change, but I’m a little surprised why a PCG-family non-CSPRNG algorithm wasn’t used: https://www.pcg-random.org/posts/a-quick-look-at-xoshiro256.html
PCG XSL RR 128/64 (MCG) could be used for 64-bit values (albeit with period 2^126 compared to xoroshiro256**’s 2^256 − 1) with 128 bits. Half the state size than xoshiro256**, and the performance might be comparable (would need benchmarking). LCG version if you want to trade PRNG quality for even more speed.
Constant variables fell out of the implementation of to-be-closed variables. As such, you can only mark local variables const, and it’s the variable that is constant, not the value. You can’t reassign the variable to a new value, but if the value is a table, the table itself can be modified.
From reading git history I see Lua switched from calling out to C random/srandom or rand/srand (depending on posix) to xorshift128+ and then to xoshiro256**. That’s a nice change, but I’m a little surprised why a PCG-family non-CSPRNG algorithm wasn’t used: https://www.pcg-random.org/posts/a-quick-look-at-xoshiro256.html
PCG XSL RR 128/64 (MCG) could be used for 64-bit values (albeit with period 2^126 compared to xoroshiro256**’s 2^256 − 1) with 128 bits. Half the state size than xoshiro256**, and the performance might be comparable (would need benchmarking). LCG version if you want to trade PRNG quality for even more speed.
To-be-closed variables, nice!
https://www.lua.org/manual/5.4/manual.html#3.3.8
The gotchas for coroutines are also interesting, e.g. the coroutine.close method.
[disclaimer: I barely know lua]
I’m just excited for const variables!
Constant variables fell out of the implementation of to-be-closed variables. As such, you can only mark local variables
const, and it’s the variable that is constant, not the value. You can’t reassign the variable to a new value, but if the value is a table, the table itself can be modified.Thanks for the clarification!