cant VS byte-unixbench

That was one of the short examples in Norvig's Python program-design course for Udacity. https://github.com/darius/cant/blob/master/library/regex-gen... (I don't have the Python handy.)

> figure out a way to do upward movement that doesn’t require annoying special casing. If you figure it out, don’t tell me since it means I’ll have to make more levels.

Don't read this, then: https://github.com/darius/cant/blob/master/examples/games/20...

As long as I'm commenting, here are some links to other console Sokobans I thought were fun (listed in the source code to mine). The sed one is nuts -- I had no idea it could do that: https://github.com/darius/cant/blob/master/examples/games/20...

I've done AoC using my own language before. As a task it's at a sweet spot for finding weaknesses in the language/library/implementation: real and varied enough to exercise your system, small chunks of work, lots of code to compare yours to, with fun and competitive juices.

The first time I did it it forced me to fix some major problems. My language would still be a handicap for me in the state it's in (though I did get on the leaderboard a couple times using it).

fwiw: https://github.com/darius/cant (haven't done this year's so far)

I've used my own hobby language Cant before, for a couple reasons: it's meant to be enjoyable to code in (at least for me), and tackling random problems like this is a good way to drive some improvements to it.

Also similar: the 'for' expression in Cant (search for "syntax: for").

Darius Bacon wrote a version of this in https://github.com/darius/cant/blob/master/library/factoring... where the "frontier" of active riders is stored in a hash table rather than a bin heap, which is almost certainly a more efficient approach. But he's not doing the bitmaps.

Thank you!

I dislike style nazis too, e.g. carping when Peter Norvig's code won't pass PEP 8.

I'm just leery of the expected cost in this kind of case. It can go on working for years until some new complication or some change in the ecosystem makes it suddenly create a really weird problem. Or when you want to try moving to a fancy new Python implementation, you find you have this friction. Matter of judgement where some chance of such messes is paid for by what it can do for you. (Of course when it's less "load bearing" the balance shifts.) With https://coverage.readthedocs.io/en/stable/ for example, it used bytecode hacks to do something you couldn't do otherwise, and that's unlikely to mess you up.

I have had old C programs go crazy years later in a really hard to debug way because newer compilers may interpret your code like your ex-wife's divorce lawyer (as Kragen put it, iirc). Back in the day a lot of us thought we had a different kind of relationship with C compilers, and it'd be fine to code to that informal social contract. (Just a loose analogy.)

I'm piddling away at https://github.com/darius/cant these days. (Some of the motivation was feeling too confined by Python, actually.) No Wasm, but I'm happy it exists! I tried to make a system like it 20 years ago (Idel) and gave up too soon.

Agreed. I used a few Rosetta Code problems in https://github.com/darius/cant/tree/master/examples and https://github.com/darius/cant/tree/master/library, but Rosetta is mostly things I don't care about.

Just for fun I tried it on my own toy language that nobody but me uses -- going to the limit in nicheness. E.g. Project Oiler problem #1 -- it's very wrong, but no shame in that.

There aren't many distro benchmarks on ARM, so I ran UnixBench for about 3 hours. https://github.com/kdlucas/byte-unixbench

Some of the most interesting benchmarks here:

Dhrystone 2: 253.2 on the Mango Pi MQ Pro, 202 on the Raspberry Pi Zero. I don't know what this number is; presumably it's not Dhrystone MIPS (VAX MIPS), because that should be closer to 1000 for both chips, and it can't possibly be Dhrystones per second, because a VAX MIPS is 1757 Dhrystones per second, so they ought to be about 1.8 million Dhrystones per second. Reading https://github.com/kdlucas/byte-unixbench/blob/master/UnixBe... leaves me no wiser.

File Copy 1024: 124.4 on the MQ Pro, 86 on the Raspberry Pi Zero. The UnixBench README says this is measured in the number of characters that can be written, read, and copied in 10 seconds; if this were correct it would mean the MQ Pro were copying 12.4 bytes per second and the Raspberry Pi Zero W was copying 8.6 bytes per second. It seems inescapable that Bret's results are incorrect by several orders of magnitude here.

C copy backwards: 1197.4 MB/s (not MiB/s as I previously read incorrectly) on the MQ Pro, 157.2 on the Zero W. Something went wrong here.

Standard memcpy: 1200.9 MB/s on the MQ Pro, 424.8 on the Zero W.

Standard memset: 2650.6 MB/s on the MQ Pro, 1699.9 on the Zero W. This seems surprisingly slow; you'd think an 8x-unrolled loop of SD instructions on a 1GHz RISC-V would memset about 5 gigabytes per second, if it got one instruction per clock, which it normally ought to. The XuanTie C906 core in the AllWinner D1 C906 is 64-bit, which is potentially an advantage for this; the analogous code for ARM6 can only write 32 bits per instruction. (The ARM has an STM instruction that stores multiple registers, but it doesn't actually run faster.) I'm not sure what happened to the extra factor of 2 in performance. Similar remarks apply to the memcpy results above.

Amazon Basics 64GB MicroSD card: MQ Pro reads sequentially at 11.48 MB/s, writes sequentially at 10.77 MB/s; Zero W reads sequentially at 21.36 MB/s, writes sequentially at 19.6 MB/s. (I'm ignoring the random reads and writes because he doesn't specify the read and write size, yet he gives the results in MB/s instead of IOPS.) Note that these are six orders of magnitude faster than the 12.4 and 8.6 bytes per second given earlier.

Unfortunately Weber doesn't link to the benchmark code or document his compilation and execution environment. Presumably the memset and memcpy results are largely measuring the performance of the libc functions, for example, so reproducing them would require knowing if he's using glibc, musl, or a C library he wrote himself.

Mostly I feel like these benchmarking results are not well enough specified to be useful, which is a shame. I'd like to be able to use this kind of benchmark to predict the performance of a system within a factor of 5 or so, but these results are too irreproducible for that.