AQA 7517 4.4.2.3: Regular expressions
The free BugBot lesson that teach this point, a robot to try it on, and the past-paper questions that test it.
What it covers
A finite state machine describes a set of strings by drawing a machine. A regular expression (regex) describes a set of strings by writing a short pattern. They turn out to be two views of the same thing, and the sets of strings they can describe have a name: regular languages.
- Languages
- The metacharacters
- Regular expressions in Python
- Regular expressions and FSMs
- Regular languages
Or do it in the simulator, with tasks that mark themselves
Lessons that teach it
- A6.4 Regular expressions and regular languages Theory of computation
The metacharacters, matching in Python, the link between regexes and FSMs, and what makes a language regular.
Try it on a robot
The task from A6.4 Regular expressions and regular languages, running here. Change the program and press Run.
The specification is AQA's own document; this page says which of our lessons teach point 4.4.2.3 and is not endorsed by the board.