Programming Language Technology

DAT151 (Chalmers) / DIT231 (GU)
Winter Term 2022 (LP2)

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News and changes

The deadline for lab 2 has been extended to Wed 30 Nov 2022 midnight.

The code from today's "Hands-on for lab 2" session is online: Haskell and Java.
Stub for today's live coding online.
First published version of this page.


Tuesday lectures are in HC2, Thursday lectures in SB-H6, with exceptions Thu 3rd Nov in SB-H5 and Tue 22nd Nov in SB-H1), starting at 13:15.

Material: plt = course book, dragon = Dragon book. Slides follow closely the plt book.

Date Time Title Material
Tue 01/11 13-15 PL Design, Compilation Phases slides, plt 1, dragon 1, live coding start
Thu 03/11 13-15 SB-H5 Grammars / BNFC / Hands-on with Lab 1 slides, plt 2, dragon 2.8.2,4.1-4.3, git, live coding start
Tue 08/11 13-15 Formal languages and parsing slides, plt 3, dragon 3,4, shift-reduce parsing LR-table LL parser code
Thu 10/11 13-15 Theory of lexing (lecture: Prabhat) slides, plt 3, dragon 3,4
Mon 14/11 23 Lab 1 deadline
Tue 15/11 13-15 * Type checking (lecture: Mohammad) slides, plt 4, dragon 5,6, script prime.c
Thu 17/11 13-15 Interpreting slides, plt 5, script
Tue 22/11 13-14 Hands-on with Lab 2 (Haskell) live coding
Tue 22/11 14-15 Hands-on with Lab 2 (Java) live coding
Thu 24/11 13-15 SB-H1 Code generation slides, plt 6, dragon 6,7, notes, prime.c, prime.j
Mon 28/11 23 Lab 2 deadline
Tue 29/11 13-14 Hands-on with Lab 3 (Haskell) live code (diff)
Tue 29/11 14-15 Hands-on with Lab 3 (Java) live code (diff)
Thu 01/12 13-15 Functional programming languages slides, plt 7, dragon 6.5,7.3, script
Tue 06/12 13-15 Type inference and polymorphism plt 7.7-9, script
Thu 8/12 13-14 Hands-on with Lab 4 (Haskell) diff start live
Thu 8/12 14-15 Hands-on with Lab 4 (Java) diff start live
Tue 13/12 13-15 Dependent types (Agda) video "Live" coding start
Wed 14/12 23 Lab 3 deadline
Thu 15/12 13-15 Preparing for the exam video Training exam Solution Answer Q1 Q1.c Answer Q3-6
Mon 09/01 23 Lab 4 deadline
Thu 12/01 8.30-12.30 Exam Exam
Mon 23/01 14.30-15.30 Exam review (EDIT 6128) Solution
Fri 27/01 23 Final lab deadline all lab returns
Tue 04/04 8.30-12.30 First reexam
Thu 24/08 14-18 Second reexam

The official course schema is in Time Edit.


The aim of the course is to give understanding of how programming languages are designed, documented, and implemented. The course covers the basic techniques and tools needed to write interpreters, and gives a summary introduction to compilation as well. Those who have passed the course should be able to

  1. define the lexical structure of programming languages by using regular expressions, explain the functioning of finite automata, and implement lexical analysers by using standard tools;
  2. define the syntax of programming languages by using context-free grammars, explain the principles of LL and LR parsing, and implement parsers by using standard tools;
  3. define and implement abstract syntax;
  4. master the technique of syntax-directed translation and its efficient implementation in their chosen programming language;
  5. formulate typing rules and implement type checkers;
  6. formulate operational semantic rules and implement interpreters;
  7. write simple code generators;
  8. be familiar with the basic implementation issues of both imperative and functional languages;
  9. master the principles of polymorphic type checking by unification;
  10. implement an interpreter for a functional language.


Andreas Abel, responsible course teacher and examiner.


Laboration times and supervision

Lab supervision is available in room ED3354 and online on Tue, Thu and Fri.

Day Time Location Supervisors
Tue 15:15-17:00 Zoom, ED3354 Andreas, Eric, Prabhat
Thu 15:15-17:00 Zoom, ED3354 Eric, Mohammad, Robert
Fri 13:15-15:00 Zoom, ED3354 Mohammad, Prabhat, Robert

The lab rooms and supervision are available from Tue 01 Nov till Fri 16 Dec 2022, except for Fri 04 Nov which is a half-day.

We use Slack to organize the lab supervision. Please join our Slack workspace.

The TAs will be present in lab rooms during lab supervision slots, available for help both in-person and virtually. To ask for help, just send a ticket request through the #queue Slack channel.

You are expected to find a lab partner, with whom you will do the labs. If you have difficulties finding a partner, please use Slack channel #lab-partner.


You have to pass the labs to pass the course. However, the course grade is determined solely by the exam.

The labs are quite substantial, so please set aside at least 30 full working hours (4 full working days) before the deadline. It is recommended to start at least 10 days before the deadline.

Labs are to be solved in groups of two. (Individual solutions are accepted per exception, please contact the course responsible.) Groups are formed on Canvas and then recreated automatically on Chalmers GitLab. After the first lab has been submitted, the groups are fixed. (Should you nevertheless need to urgently change to group, please contact the course responsible.)

The labs will be published in your Gitlab group and a solution repository will be created for you there. Submission of your solution is by creating a submission tag in the repository. Please read the detailed lab instructions at:

Keep your lab solutions confidential! If you post problems and discussions around the labs on Canvas etc., make sure you do not give away the solution.

We guarantee two gradings per lab: one for the version submitted before the ordinary deadline for that lab, the other for a resubmission before the final deadline. If your first submission does not build or does not pass the testsuite, you will just get fails testsuite as grading.

As part of the grading, you may be asked to explain your solution in person to a course teacher. Be prepared to get a call for such an explanation meeting. In particular, make sure you understand all parts of the solution (good documentation helps!).


The written exam determines the course grade, the usual grading scales apply: Chalmers: 5, 4, 3, U; Gothenburg University: VG, G, U.

Exam dates: 12 Jan 2023 am J, 04 Apr 2023 am J, 24 Aug 2023 pm J.

The exam tests the understanding of the course contents from a more high-level view, e.g., the underlying theoretical concepts. The exam has the same structure as these old exams (download as archive).

Further, here are some old exercises and solutions to prepare for the exam.


The main book will be one that developed from earlier editions of this course:

Aarne Ranta
Implementing Programming Languages. An Introduction to Compilers and Interpreters, College Publications, London, 2012. Web page (with extra material and links to selling sites)

Please also check the errata page (welcome to submit errata not covered there yet).

If you are really interested in the topic, for instance, if you want to continue with the Compiler Construction course, you should also consider the Dragon book,

Aho, Lam, Sethi & Ullman
Compilers Principles, Techniques & Tools, Second edition, Pearson/Addison Wesley 2007.

Both books are available at web bookshops. The main book will also be sold at Cremona.

A good (yet slightly dated) introduction to monads in Haskell, useful for implementing interpreters, type checkers, and compilers, is this article:

Philip Wadler
Monads for functional programming. In Advanced Functional Programming, First International Spring School on Advanced Functional Programming Techniques, Båstad, Sweden, May 24-30, 1995.

It also contains an introduction to parser combinators.


If you are solving the labs on your own Windows machine, you might have to obtain some command-line developer tools stemming from the Unix world, like make, tar, etc. (These are by default available on Linux and can be installed from Xcode on macOS.) Windows from version 10 offers installation of a Linux distro via the Windows Subsystem for Linux (WSL). Another popular option is MSYS2 which is also bundeled with Haskell stack.


We use the BNF Converter (Homepage | Hackage | Stackage | GitHub).

Download and installation instructions at

When using the Java backend, you will need either ANTLR or the CUP libraries and either JFLex or the JLex libraries. CUP has seen incompatible changes in its interface; thus, the version you need may depend on your BNFC version.

Java/CUP Instructions for BNFC ≥ 2.8.2 (uses CUP v0.11b)

Download the JAVA archives for CUP v11b, CUP v11b runtime, and JLex. Make sure they are placed in your classpath, for example (Linux / macOS) by storing these jars in $HOME/java-lib/ and adding the following line (or a suitable variant) to .bashrc (could also be .bash_profile or similar):

    export CLASSPATH=.:${HOME}/java-lib/java-cup-11b.jar:${HOME}/java-lib/java-cup-11b-runtime.jar:${HOME}/java-lib/JLex-1.2.6.jar:${CLASSPATH}

(Java/CUP Instructions for BNFC ≤ 2.8.1 (uses CUP v0.10k) can be found on older versions of this page.)

Student representatives

Student representatives for DAT151 Programming language technology.

Program Name