In this post we will see how to extend reverse mode automatic differentiation to a language with first class function types, function application and lambda-abstraction. This method is not new, but we will give a new derivation of it by showing how it arises universally from noticing that the category of “additive lenses” is cartesian closed. In the end we will see that this idea sounds like it should revolutionise machine learning, but then doesn’t.

Some interesting ideas, although I won’t claim that I understand them all.

If you’re building a new CI system/IaC platform/Make replacement: please just let me write code to dynamically create the workflow/infrastructure/build graph.

Also why universal healthcare matters. Gotta maintain all parts of a system!

via: https://mit.edu/6.1800/www/readings/01-wrong.shtml

The first reason, then, that we care about low-level is that it allows us to make better choices. We can make better software by starting in the right place, with the right frame and the right stack. Low-level programming allows us to build trucks instead of Trucklas.

I love Ben’s work, but he has a bad habit of not giving credit where it’s due, and makes him come off as smug in his writing. Yes, I too care about performance in apps. But this should not be the sole decision-maker when picking the technology stack.

I don’t mind the ways in which my job is dysfunctional, because it matches the ways in which I myself am dysfunctional: specifically, my addiction to being useful.

Talk from the Roguelike Celebration 2018

Very nice software architecture talk. Patterns discussed: composition over inheritance, type objects, commands/actions.

How we handle 92 million compilations a year without everything catching fire

The thing that would actually help an underperformer improve is to teach or (even better) show them how to do a better job and the same is true for models.

Blog posts, talks, and essays that changed how people think about dependency management.

My engine supports detailed changes to world geometry - adding and removing matter both smoothly or with sharp edges. It also supports non-destructive changes like moving a hole around, or creating a tunnel and walking through it - and then seeing it disappear behind you. I’m excited about these non-destructive changes in particular as they enable a lot of interesting gameplay mechanics.

Very impressive!

Vanilla teleporters in Minecraft. Nice.

If we want to build robust systems in which humans play a part, we cannot write off human decisions as random. We must investigate what made the human act that way because that’s the only way we can improve system robustness. I’m not making a philosophical statement by saying human behaviour isn’t random – it’s a practical standpoint for the purpose of safety engineering. Human decision-making never fails. Instead, human error is a symptom of a system that needs to be redesigned.

Interesting idea.

You really gotta work hard to meet people where they are and get them on your side.

via: https://spritely.institute/news/goblinshare-secure-peer-to-peer-file-sharing-with-goblins.html

Fil-C is a fanatically compatible memory-safe implementation of C and C++. Lots of software compiles and runs with Fil-C with zero or minimal changes. All memory safety errors are caught as Fil-C panics. Fil-C achieves this using a combination of concurrent garbage collection and invisible capabilities (InvisiCaps). Every possibly-unsafe C and C++ operation is checked. Fil-C has no unsafe statement and only limited FFI to unsafe code.

via: https://graydon2.dreamwidth.org/320265.html

This talk is an extension of my earlier Data Replication Design Spectrum blog post. The blog post was the analysis of the various replication algorithms, which concludes with showing that Raft has no particular advantage along any easy analyze/theoretical dimension. This builds on that argument to try and persuade you out of using Raft and to supply suggestions on how to work around the downsides of quorum-based or reconfiguration-based replication which makes people shy away from them.

More techniques from the math mines