Machina ex RegEx

Prof. Dr. Mirco Schoenfeld

Motivation

https://regexr.com/

And today…

Finite-state automata

https://imgur.com/gallery/most-useless-machine-ever-FRflC

From Regex to machines

Today, we will introduce a system that
can evaluate regular expressions.

Finite-state automata

Such systems are called Finite-state automata (FSA)

finite-state machines,

finite automata,

or simply state machines.

Finite-state automata

An FSA is an abstract machine that can be in
exactly one of a finite number of states at any given time.

FSA can change from one state to another in response to inputs.

Finite-state automata

FSA are all around us!

https://en.wikipedia.org/wiki/File:Compass_vending_machines_at_King_George_station.jpg

https://commons.wikimedia.org/wiki/File:Tornelli.jpg

https://www.nw.de/nachrichten/zwischen_weser_und_rhein/23904169_Grillwurst-to-go-Hier-stehen-Fleischautomaten-in-Ostwestfalen-Lippe.html

https://www.kikkoman.com/en/culture/foodforum/trends-in-taste/36-4.html

https://dauer-aufzug.de/aufzuege/spezialaufzuege/historische-aufzugsanlagen/