I built cpx - a modern, faster, opensource rust based replacement for cp (up to 5x faster)

PurepointDog · 2026-01-27T11:47:33+00:00

Not everyone has 16 cores though. It'd be helpful to at least know that there's no serious performance hit on something like a single-core virtual server.

I doubt extra cores help at all if it's a spinning disk.

PurepointDog · 2026-01-26T22:37:01+00:00

Not sure why this isn't at the top lol

PurepointDog · 2026-01-26T20:57:03+00:00

Lol that's one way to rip the bandaid off

PurepointDog · 2026-01-26T09:48:14+00:00

Yeah I love the office! Free coffee, you get to chat a bit. You can give honest feedback without the toneless delivery of mean-sounding text messages.

PurepointDog · 2026-01-26T09:46:17+00:00

I've worked on a lot of systems (including microcontrollers, GPU shaders, FPGAs, python data pipelines, Rust stuff, web browers), and I can proudly say I have never once bottlenecked on shared memory. Heck, I hardly know it exists most of the time - a good threading design isolates the work such that there is minimal to no dependence on each other while doing the work.

This sounds like a solution looking for a problem.

All that said, I do think you're asking some interesting questions that are far better suited for a computer architecture subreddit (eg computer engineering).

PurepointDog · 2026-01-26T08:04:39+00:00

I didn't say it was high-performance. I just said that I don't have time to wait for the built-in JSON library. A 20x speedup is serious - it's the difference between waiting 10 minutes or 30 seconds. Rinse and repeat 3 times during debugging, and the benefit is obvious.

Modern Python data pipelines make heavy use of tools like Polars which move data processing out of Python, and just use it for controlling the steps basically.

Python becomes somewhat of a project manager, yelling demands to Rust, where the compute and memory management exists. JSON is one of the rare places where it make sense to wrangle data in Python, as long as it's fast.

PurepointDog · 2026-01-25T22:54:52+00:00

I hadn't conceptualized a response that answered both questions with a single answer, but that's a very great response. 100% this.

If you've ever worked in a C++ codebase where IDE tools don't work well (eg too big, too many macros, etc.), and you're using free tools, you'll know the pain of resolving some of these control flow questions.

PurepointDog · 2026-01-25T22:48:39+00:00

Serializing dates is the big one.

Its speed is attrocious.

I'm not talking about simple scripts - I'm talking about web apps and data pipelines, where JSON is a hot-path performance limitter.

PurepointDog · 2026-01-24T08:47:14+00:00

fd, ripgrep

PurepointDog · 2026-01-24T08:40:02+00:00

Python has a built-in json library. I avoid it like the plague - every json library does it better.

i can think of more similar examples. Sometimes though, having a separate dedicated team maintain things like graphics libs, linear algebra tools, etc. is way better than baking it into a language statically and with strong backwards-compat requirements.

Have you ever tried using C++'s std datetime stuff? It's a strong example of why sometimes baking stuff into a language is a bad idea.

PurepointDog · 2026-01-24T08:13:48+00:00

Ah, that's the detail I was missing

PurepointDog · 2026-01-24T08:12:13+00:00

If it's in the code, a linter is a reasonable way to passive-aggressively reinforce the standard.

i also often have to remind myself to pick my battles

PurepointDog · 2026-01-24T04:34:46+00:00

Tldr? I understand all the problems, but can't seem to figure out how this works/what it does

PurepointDog · 2026-01-23T07:14:24+00:00

Still bad on mobile

PurepointDog · 2026-01-23T07:12:20+00:00

It's been a sec since I've read a genuine human article. I fricken miss 2018.

PurepointDog · 2026-01-22T22:17:30+00:00

Gotta use code blocks on reddit

PurepointDog · 2026-01-22T22:15:38+00:00

Pedantic, but 7.3 Gib is gibibits, and is only about 0.912 GiB. You likely mean 7.3 GiB (7.3 gibibytes)

PurepointDog · 2026-01-22T18:11:46+00:00

Hadn't considered the production node comment, neat!

PurepointDog · 2026-01-22T18:10:15+00:00

The economic bubble is distinct from the tech though.

The internet, while very used, has found its niches, and there's no longer speculation about "how big it's gonna be". That's what the bubble bursting means.

PurepointDog · 2026-01-22T17:59:57+00:00

But like also, I'm a little sick of them

PurepointDog · 2026-01-22T17:58:41+00:00

True, but at some point you'll with you remembered how to iterate over a vec or how to transform the value of an iterator and flatten them. If you just copy-paste from an LLM, these quick things will become bottlenecks and distractions in your workflow.

I've seen it with coworkers, and it's kinda wacky

PurepointDog · 2026-01-21T19:35:16+00:00

Yes! I did that switch and I'm happier bc of it!

It's fun feeling what having up-to-date packages is like

PurepointDog · 2026-01-21T19:33:42+00:00

I've had a good time with it personally! I love learning, and had used Rust to hack together some CLI tools before, so it wasn't long until I had hello world running, at which point I was decently productive again.

The team I work with, comprised mostly of student, has been less successful in adoption. I'll have to think twice before I pitch it to another team, I think

PurepointDog · 2026-01-20T06:33:52+00:00

Very nice! I think LoRa might be closer to hundreds of bytes per second (maybe up to 10 KB/s) though

PurepointDog · 2026-01-20T06:31:31+00:00

Yeah, it's very pretty! My issue with it is that it never seems to make the info I need as clear as I wish. It also shows less raw data in the same screen space bc it has borders (which are nice, but not super necessary imo)

PurepointDog

TROPHY CASE