Language Processors (F29LP)

Course overview

Welcome to the Language Processors webpage. In a nutshell, this course says:

“What is a computer language, really? Well, let’s generate the language by recursive rules (or automata—same thing) … then let’s give the language semantics …”

I’m co-lecturing this course with my colleague Arash Eshghi.

Lecture times

- Mondays at 14:15 in EM3.36.
- Tuesdays at 10:15 in EM1.83.
- Tuesdays at 13:15 in EM1.82.

Please also read the following:
- How to answer a programming question.
- Some comments on how to answer the question.


The videos will be updated as they are created.

Lecture of Monday 7 January at 14:15
Watch it and/or read the slides for lecture 1.
See the regex resources.
Lecture of Tuesday 8 January at 10:15
Watch it and read lecture 2, on formal grammars.
Lecture of Tuesday 8 January at 13:15
Watch it and read lecture 2, on formal grammars.
Lecture of Monday 14 January at 14:15
Watch it.
Lecture of Tuesday 15 January at 10:15
Watch it.
Lecture of Tuesday 15 January at 13:15
Watch it.
Lecture of Monday 21 January at 14:15
Watch it.
Lecture of Tuesday 22 January at 10:15
Watch it. We make a start on automata.
Lecture of Tuesday 22 January at 13:15
Watch it.
Lecture of Monday 28 January at 14:15
Watch it.
Lecture of Tuesday 29 January at 10:15
Watch it.
Lecture of Tuesday 29 January at 13:15
Watch it.
Lecture of Monday 4 February at 14:15
Watch it.

See also last year’s lectures.

The Rules

1. Turn up!
2. Understand lecture materials as you get them.
3. A student who thinks “I don’t understand this now; I’ll sort it out during the holidays” is in denial (look at 1m03s).
4. Rules 1-3 above apply especially to those who believe rules 1-3 above don’t apply to them.

List of lecture slides


Exercises (Labs) …

… are here.


- Tutorial I.
- Tutorial II.

Regex resources

- debuggex, which draws pictures of the regex (see this example), is fantastic.
- regex101, which you could test on The Jabberwocky.
- A page on regular expressions in Perl.
- This tutorial on regular expressions.
- This advanced page on sed.
- The lightweight regexpal and rather heavier-weight regexr.

Automata resources

Lewis Maitland kindly drew my attention to these two great tools:
- An automaton simulator.
- A tool for converting a regex to an NFA or DFA.
- For examples of automata “in nature”, see the following:

If you find an online tool for generating parse trees given a grammar, or for converting between context-free grammars, PDAs, and parsers, then please let me know.

The following are not automata but they’re so funny, I’ll mention them anyway:

Grammar resources

- The Context-Free Grammar developer.
- See the online production grammar tool.
- Jison converts context-free grammars to Javascript, you can try it online.
- Here’s quite a nice parse tree generator
- And here’s another

Other course resources

You might like to have a look at:

- I really like bits of Jarkko Kari’s notes on Automata and formal languages (from his course at the University of Turku in Finland).
- Eitan Gurari’s course notes on formal grammars.
- Andrew Black’s course on computational structures is a model of online accessibility.
- Computer science degrees often include a course on automata and formal languages. It is often called “Automata and Formal Languages”. Just search Google for automata and formal languages solutions, and explore.
- The Wikipedia page on formal languages.
- The Wikipedia page on the Chomsky hierarchy has a good cheat-sheet at the bottom.

Mock paper and past exams

A mock paper for my half of the course is available, along with the 2014 exam and resit:
- Without solutions (do this first).
- With solutions.
- The exam and resit from last year are in Vision under Learning Materials.

A bit about me

I am a researcher in theoretical computer science. My research is mostly in formal logic.
Everybody calls me Jamie but my name is actually Murdoch. You can contact me by e-mail on “gabbay at macs hw ac don’ttypethis uk”. My office is G.50 Earl Mountbatten Building.

The students …

… should be mostly third year undergraduate students.

If you don’t know what an undergraduate student looks like, think of minions, but less yellow.