Reduktionen

Motivation Intuitiv können wir uns vorstellen: Einige Mengen sind komplexer als andere. Die Elemente mancher Mengen zu finden ist schwerer als das bei anderen der Fall ist. Mit dem Konzept der Entscheidbarkeit und Semientscheidbarkeit haben wir bereits eine Kategorisierung geschaffen, die uns ermöglicht Sprachen1 bezüglich ihrer »Schwierigkeit« einzuordnen. Nun gibt es viele Sprachen, die gar nicht semientscheidbar sind und sich deswegen untereinander nicht durch Entscheidbarkeitsbegriffe ordnen lassen. Das ist ganz schön doof.

Installing Podman and friends on NixOS

Note: There is an open pull request for a podman module that will make all of this easier. First you install all the software the normal way: 1 2 3 4 5 6 7 environment.systemPackages = with pkgs; [ podman runc skopeo conmon slirp4netns ]; But there is some additional configuration you need to do. You need to give the user you want to run podman on additional uids and gids so that they be used as virtual uids and gids in the containers:

Setting up a local Postgres dev database on NixOS

I recently had to setup a local database for testing purposes. The last time I did that was on Mac OS. On that platform the awesome Postgres.app is available that sets up a dev database in seconds. (Seriously, if you are a developer on Mac you should check that out.) On Linux --- and in my case NixOS -- the process is more involved unfortunately. You can't (as far as I know) just put something into your dev environment shell.

Linux Software you should check out

Ripgrep Imagine grep or pt, but really really fast. Skim With Skim you can really easily find files in the terminal. It easily integrates with other UNIX commands. I use the following to easily open folders: alias c "cd (sk)". Entr This is also a utility that can be integrated with other commands. It's a file watcher that just works. I use it with nix-build to get it to file watch.

My Backup configuration: Backblaze B2 & Duplicati

A short while ago I had a catastrophic drive failure. While I was able to reuse the drive itself, all my files were lost. I have all my important files in git Repos. That includes my whole system configuration. (The beauty of nix.) This was the saving grace. I could recover my setup quite easily, but not as easily as I had hoped. It took up almost an entire day.