COSC261-21S1 (C) Semester One 2021

Formal Languages and Compilers

15 points

Start Date: Monday, 22 February 2021
End Date: Sunday, 27 June 2021
Withdrawal Dates
Last Day to withdraw from this course:
  • Without financial penalty (full fee refund): Sunday, 7 March 2021
  • Without academic penalty (including no fee refund): Friday, 14 May 2021


This course deals with fundamental concepts and techniques in computer science. It covers automata, formal languages, compilers, computability and complexity theory.

We will cover topics from the following list:
• finite automata and regular expressions
• pushdown automata and context-free grammars
• Turing machines and recursively enumerable languages
• undecidability and the halting problem
• complexity classes and the P=NP problem
• lexical analysis and scanners
• syntactic analysis and parsers
• semantic analysis and optimisation
• code generation

Learning Outcomes

  • After successful completion of this course, students are able to:
  • differentiate formal languages at the various levels of the Chomsky hierarchy,
  • compare the expressiveness of different kinds of automata,
  • apply conversions between languages, automata, regular expressions and grammars,
  • separate undecidable, inefficiently decidable and efficiently decidable problems,
  • use familiar techniques to generate automata and grammars for unfamiliar languages,
  • outline the structure of compilers,
  • analyse the lexical and syntactic structure of programs,
  • use regular expressions and context-free grammars for constructing compilers,
  • produce recursive-descent parsers, and
  • change components of a compiler to deal with new program constructs.


(1) COSC121 or COSC131; (2) COSC122; (3) MATH120

Timetable Note

Depending on final student numbers, some of the advertised lab/tutorial streams may not run. Final lab/tutorial options will be available for self-allocation closer to the start of the semester through My Timetable.

Course Coordinator / Lecturer

Walter Guttmann


Kourosh Neshatian


Assessment Due Date Percentage 
Quizzes 15%
Assignment Superquiz 10%
Lab Test 15%
Final Exam 60%

Textbooks / Resources

No textbooks are required, but see the following book for additional information:
• Carol Critchlow and David Eck; Foundations of Computation; version 2.3.1, 2011, available here

More advanced or comprehensive books are:
• Michael Sipser; Introduction to the Theory of Computation; third edition, Cengage Learning, 2013
• John Hopcroft, Rajeev Motwani and Jeffrey Ullman; Introduction to Automata Theory, Languages and Computation; Pearson, 2006
• Dexter Kozen; Automata and Computability; Springer, 1997
• Reinhard Wilhelm and Dieter Maurer; Compiler Design; Addison-Wesley, 1995
• Niklaus Wirth; Compiler Construction; Addison-Wesley, 1996
• Alfred Aho, Monica Lam, Ravi Sethi and Jeffrey Ullman; Compilers: Principles, Techniques, and Tools; second edition, Pearson, 2007


There are several important documents available online about departmental regulations, policies and guidelines at the following site. We expect all students to be familiar with these.

Notices about this class will be posted to the class forum in the Learn system.

COSC students will also be made members of a class called “CSSE Notices”, where general notices will be posted that apply to all classes (such as information about building access or job opportunities).

Additional Course Outline Information

Grade moderation

The Computer Science department's grading policy states that in order to pass a course you must meet two requirements:
1. You must achieve an average grade of at least 50% over all assessment items.
2. You must achieve an average mark of at least 45% on invigilated assessment items.
If you satisfy both these criteria, your grade will be determined by the following University- wide scale for converting marks to grades: an average mark of 50% is sufficient for a C- grade, an average mark of 55% earns a C grade, 60% earns a B- grade and so forth. However if you do not satisfy both the passing criteria you will be given either a D or E grade depending on marks. Marks are sometimes scaled to achieve consistency between courses from year to year.

Students may apply for special consideration if their performance in an assessment is affected by extenuating circumstances beyond their control.

Applications for special consideration should be submitted via the Examinations Office website within five days of the assessment.

Where an extension may be granted for an assessment, this will be decided by direct application to the Department and an application to the Examinations Office may not be required.

Special consideration is not available for items worth less than 10% of the course.

Students prevented by extenuating circumstances from completing the course after the final date for withdrawing, may apply for special consideration for late discontinuation of the course. Applications must be submitted to the Examinations Office within five days of the end of the main examination period for the semester.

Indicative Fees

Domestic fee $877.00

International fee $4,438.00

* All fees are inclusive of NZ GST or any equivalent overseas tax, and do not include any programme level discount or additional course-related expenses.

For further information see Computer Science and Software Engineering .

All COSC261 Occurrences

  • COSC261-21S1 (C) Semester One 2021