Automata, Built For Comfort or Speed

It’s been a while. February was the last entry in this Quamina Diary; I never stopped working on it but there hasn’t been much blogworthy. This piece offers a progress update for those who’ve been entertained by Quamina, and also a pleasing (well, to me anyhow) dip into finite-automata theory and practice. With numbers and graphs and a bluesman! Since it’s been so long, here’s what Quamina, a Go-language library, does: You can add “Patterns” to a Quamina instance, they match the values of fields in JSON objects, and then you show Quamina a JSON “Event” and it’ll tell you which Patterns matched it. It’s pleasingly fast and in many cases the speed is not strongly affected by the number of Patterns you’re trying to match. The last release, V2.0.2 back in March, marked the arrival of a reasonably-full regular-expression dialect into Quamina’s pattern language, so you can say, for example, that the Filename field has to match map-[0-9]+.(png|pdf|jpe?g). Regular expressions were a lot of…