Type-driven configuration management with Propellor

Thanks for a nice writeup. There are more property composition functions than the 4 listed; only so much haskell code can fit on a slide. ;)

Incidentially, Arch Linux users may be interested to learn that I merged support for Arch Linux into propellor this weekend, thanks to Zihao Wang. An interesting part of that patch was that Property DebianLike and Property Linux stopped being synonyms, since propellor now knows that Linux includes ArchLinux too. This let the type checker prove that some properties that had been marked as Property Linux were actually Debian-specific, due to using apt deep in their implementations.