Steve Klabnik

“The most violent element in society is ignorance.” - Emma Goldman

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How often does Rust change?

I’ve been thinking a lot lately about how often Rust changes. There are some people that assert that Rust stays fairly static these days, and there are some people who say Rust is still changing far too much. In this blog post, I want to make a data driven analysis of this question. First, I will present my hypothesis. Next, my methodology. Then, we’ll talk about the results. Afterward, we’ll discuss possible methodological issues, and possible directions for further research.

As said on twitter:

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The hypothesis

My personal take on Rust changing: to me, it feels like we had more change in the past than we have today. The changes are also getting more minor. This will be my hypothesis.

The methodology

There are tons of different ways that we could measure the question “how often does Rust change?” So before I started collecting data, I had to decide some details.

I realized that my...

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“C is how the computer works” is a dangerous mindset for C programmers

A long time ago, I wrote “Should you learn C to “learn how the computer works”?”. This was part 1 in a three part series. A year later, I got around to part 2, ““C is not how the computer works” can lead to inefficient code”.

It’s been five more months. I don’t think I really want to write out the third part; I expected this to be a quick series of blog posts, not something that was on my plate for a year and a half. Here’s the thesis of part 3:

Part three is going to show what happens if you make a mistake with the ideas from part two. If you incorrectly assume that C’s abstract model maps directly to hardware, you can make mistakes. This is where UB gets dangerous. While you can take advantages of some properties of the machine you’re relying on, you have to know which ones fit within C’s model and which ones don’t.

I honestly don’t feel like writing more than that, so I’m just...

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A sad day for Rust

actix-web is dead.

This situation is bad, from all sides. When Rust was a tiny, tiny community, I thought to myself, “wow, I wonder how long this will last? Probably 1.0 will kill it.” Sort of playing off of Eternal September, I assumed that over time, the community would grow, and we’d encounter problems.

Today is the first day where I say to myself, okay, has that happened?

This story is not super clear-cut. I’m not going to link to a dozen citations, or try to prove that I’m some sort of neutral party here. I’m going to give you account of this story as I remember it and as I felt it. Because this isn’t really about playing judge. This is about thinking about the future.

It’s been very clear from the beginning that the Rust project saw Rust as more than just the language. The community and the people mattered. From the earliest days, leadership explicitly took the position that it...

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“C is not how the computer works” can lead to inefficient code

A little over a year ago, I wrote “Should you learn C to ‘learn how the computer works’”. It was a bit controversial. I had promised two follow-up posts. It’s taken me a year, but here’s the first one.

In that post, I argued that C doesn’t “work like the computer”, but rather, by a concept called the “C abstract machine.” It happens to be close to how computers operate in some sense, but that when you write C, you’re writing for the abstract machine, not the computer itself. Here’s the trick, though: the C abstract machine doesn’t define every single aspect of how computation happens. And so sometimes, you can write code in two different ways, that the C abstract machine says are equivalent, yet are not equivalent in performance. This means that, even if you buy into my original point, you still need to know the boundaries of this definition, and can exploit those boundaries in...

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Porting steveklabnik.com to Workers Sites and Zola

One fun thing about having a personal domain is that you can keep the contents the same forever, but take a few days every so often to port it to some new stack you want to try out.

A while back, I had my site on GitHub Pages using Jekyll. This has long been the sort of default, go-to stack for me. At some point, I decided to simplify even further, and wrote a small script to take the few Markdown files I have and just make HTML out of them. I then used Netlify to do the hosting. I wanted to try out their legendary ease of use, and it was indeed super simple.

Earlier this year, I took a job at Cloudflare to work on part of Cloudflare Workers. To get more familiar with the project I’d be working on, Workers KV, I came up with a plan: I’d put the Markdown files into KV, and then write a worker in Rust and WebAssembly that would generate the HTML on the fly, and run that in a Worker. This...

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I’m joining Cloudflare

Cloudflare logo.png

Yesterday, I signed an offer letter from Cloudflare. I’ll be the product manager of Storage, which is the part of the company that’s working on data storage products for the Cloudflare Workers platform. I’ll be starting at the end of the month.

I think a lot of you will say “that makes perfect sense,” but many more will say “wait, what?”. I hope this post will make things a bit more clear.

Before we start, I also want to say that I’ll still be continuing my work on Rust, though obviously in a more limited capacity. I’ll still be working on revisions to The Rust Programming Language, and doing core team work, for example.


Before I worked on Rust, I worked on and with Ruby on Rails. When I got out of the web application game, the hot topic was this new “platform as a service” stuff. I’ve been watching all of the latest changes from afar, and they’ve been quite interesting. I’ve...

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What comes after “open source”

In a previous post, I discussed the history of open source, and ended with this claim:

Today’s developers have never learned about this history, or don’t care about it, or actively think it’s irrelevant. … For the same reasons that “open source” came up with a new name, I think the movement that will arise from today’s developers will also need a new name.

We talked about the ideological history of open source, but that’s not what developers object to, really. I don’t think developers are moving back towards a world of making source code private. Instead, it’s something related to a very old discussion in free software. To quote the FSF:

“Free software” means software that respects users’ freedom and community. Roughly, it means that the users have the freedom to run, copy, distribute, study, change and improve the software. Thus, “free software” is a matter of liberty, not price. To...

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Rust has finally outgrown me

Today is a very interesting day. It’s giving me a lot of feels. Today is Rust Latam, a Rust conference in Montevideo.

And I’m not there.

This is significant because, as far as we know, I’m the only person who has been to every Rust conference in existence so far. I went to RustCamp, all three RustConfs, all five RustFests so far, all three Rust Belt Rusts. One RustRush. Am I forgetting any? Thirteen Rust conferences in the past four years.

I really wanted to attend Rust Latam. The main organizer, Santiago, has been a friend for a very long time. It’s amazing that we’re getting a new conference in this part of the world. There’s been a lot of energy with Rust there for quite a while. It would have been nice to meet all those people whose tweets I’ve seen.

But in the end, I’m still between jobs (news on that soon, hopefully!), and spending that money would be irresponsible. I’m just...

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Learning Ada

I decided to try and learn Ada. I love programming languages. This post documents my attempt, and explains what I learned. This is pretty stream of consciousness and basically is a bunch of random notes, so if you hate that, better close the tab. I typed my thoughts up pretty raw, so I may be incorrect in places too. Let me know if you know the answer to something I don’t!


The first step, of course, is to google:

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Great! I know that Adacore are sort of the stewards of Ada? Vaguely, that might be wrong. Let’s look at all three of those.

Learn.adacore.com is an interactive learning platform designed to teach the Ada and SPARK programming languages.

Ah, that’s awesome! No installation needed.

The second one looks extremely like spam. It does have a page of learning materials that look legit enough. I wonder if this is a low-effort attempt to make money through ads. Or maybe it’s...

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The culture war at the heart of open source

There’s a war going on. When isn’t there a war going on? But I’m not talking about a physical war here: I’m talking about a war over meaning. This particular war is a fight over what “open source” means.

Let’s take a few steps back.

The Free Software Foundation

People organize into groups for many reasons. This story starts with the story of an organization called the “GNU Project.” It was started in 1983, and here’s the initial announcement on USENET. I’ve pulled out four important paragraphs:

Starting this Thanksgiving I am going to write a complete
Unix-compatible software system called GNU (for Gnu’s Not Unix), and
give it away free to everyone who can use it. Contributions of time,
money, programs and equipment are greatly needed.

I consider that the golden rule requires that if I like a program I
must share it with other people who like it. I cannot in good
conscience sign a...

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