orlp

91 ms·

421.
by orlp 4y ago
Modern processors execute out-of-order (reordering instructions) and are superscalar (they execute more than one instruction per cycle). By providing multiple independent data paths in the tight merging/partitioning loops we can keep t
422.
Show HN: Glidesort, a new stable sort in Rust up to ~4x faster for random data(github.com)
389 points by orlp 4y ago|70 comments
423.
by orlp 4y ago
This is very similar to Wikitrivia: https://wikitrivia.tomjwatson.com/ , which asks you to place general historical concepts/events on a timeline.
424.
by orlp 4y ago
That's a bit of an unfortunate name clash with PRQL, also pronounced prequel: https://prql-lang.org/
425.
by orlp 4y ago
Hey all, this is my first ever published blog post, so in case you have any feedback not just on the content but on the format as well, I'm all ears.
426.
Ordering Numbers, How Hard Can It Be?(orlp.net)
7 points by orlp 4y ago|2 comments
427.
by orlp 4y ago
Because always returning a positive result from the remainder is incredibly unnatural. You can get this behavior through Python's definition trivially using `a % abs(b)`, making rem_euclid less flexible as well. The reason it's in
428.
by orlp 4y ago
Rust's rem_euclid is still wrong for negative moduli. To see why, remember that we want n = remainder + quotient * divisor. Now look at the horrible mess that is div_euclid: > In other words, the result is self / rhs rounded to
429.
by orlp 4y ago
https://cr.yp.to/publicdomain.html I'm not taking a stance, I'm just the messenger.
430.
by orlp 4y ago
> Such numbers must exist because there are only a countably infinite number of numbers that can be described using a finite collection of symbols, but there are an uncountably infinite number of real numbers. So not only are there numb
431.
by orlp 4y ago
In my experience the new strategy is to just send an email with no body, no title, optionally with an image of a conventionally attractive lady, in the hope people respond after which they're automatically whitelisted (as there's
432.
by orlp 4y ago
The use case for DuckDB is the that the vast majority of analytics aren't on "big data", but also aren't "small-ish". If your data fits on a single machine, DuckDB will allow you to query it at great speed. I d
433.
by orlp 4y ago
I think there's a formatting miscommunication here. The person you're replying to meant going from n^2 -> n^1.5, which isn't just a linear speedup. E.g. processing 1000 elements with an n^2 algorithm requires a million ope
434.
by orlp 4y ago
It's a two steps forward, one step backwards thing. The things you are noticing really are a step backwards, but that doesn't mean progress overall is going backwards.
435.
by orlp 4y ago
> This clock solves that problem. In English! In Dutch this would actually create a problem, as when it is 3:45 we say it is "15 before 4". I noticed that I actually struggled to interpret the wobbly clock when it was close t
436.
by orlp 4y ago
...for now :)
437.
by orlp 4y ago
I haven't compared because they're apples and oranges. The radix sorts do not allow a custom comparison function. I would assume that they're faster, especially if using SIMD.
438.
by orlp 4y ago
Hey, the open source release will coincide with the FOSDEM presentation, so in a little under three weeks it will be under my Github account github.com/orlp.
439.
by orlp 4y ago
For C#, it is very similar to Rust, so I would say yes. I'm too unfamiliar with the JVM and its performance characteristics to say for sure for Java, but probably also yes. However, the performance characteristics of Python are so diff
440.
by orlp 4y ago
Yes, it is.
441.
by orlp 4y ago
At FOSDEM 2023 I will be presenting glidesort in the Rust room. It is a new stable sorting algorithm that is a hybrid of quicksort and mergesort which is much faster for random data, while still taking full advantage of pre-existing order o
442.
by orlp 4y ago
I'm interested in possibly contributing / optimizing in polars, I would be curious to hear from a user first-hand which things are painful and/or slow still.
443.
by orlp 4y ago
Fraud detection. Detecting and analyzing anomalous flows of financial transactions requires you to look at multi-hop series of transactions.
444.
by orlp 4y ago
Doesn't this violate strict aliasing? E.g. what if we do this? void foo(struct_a *a, struct_b *b) { a->x = 0; b->x += 1; a->x = 0; } Strict aliasing allows the compiler to elide the second a->x = 0. But if we use y
445.
by orlp 4y ago
Who is Terrence Tao? Do you mean Terence Tao? (if we are nitpicking about typography...)
446.
by orlp 4y ago
Ah, fair enough.
447.
by orlp 4y ago
I have never in my life seen it spelled krokette. Only kroket.
448.
by orlp 4y ago
Even knowing what goes on, I don't think it makes sense, so you're further than I am :)
449.
by orlp 4y ago
> That said, the pop implementation seems faulty in that it does not appear to deallocate empty chunks. Does Rust have any non-obvious magic here? No, the only magic here is my utter lack of testing for throwaway HN code :) A corrected i
450.
by orlp 4y ago
Yes. Down on the Wikipedia page there is a fairly basic game that you can convince yourself is impossible to win with 100% probability without communication: https://en.wikipedia.org/wiki/Quantum_pseudo-telepathy#Green.

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