Formal Languages and Compilers

Fundamental familiarity with the theory of formal languages. The ability of a compiler construction.

Familiarity with formal languages and their models. Grasp of compiler construction.

The IFJ class gives a clear, comprehensive introduction to formal language theory and its applications in computer science for undergraduate students. It covers all rudimental topics concerning formal languages and their models, especially grammars and automata, and sketches the basic ideas underlying the theory of computation, including computability and decidability. Emphasizing the relationship between theory and application, the class describes many real-world applications, including computer science engineering techniques for language processing and their implementation.

    More specifically, IFJ

• Covers the theory of formal languages and their models, including all essential concepts and properties
• Explains how language models underlie compilers
• Pays a special attention to programming language analyzers, such as scanners and parsers, based on four language models-regular expressions, finite automata, context-free grammars, and pushdown automata
• Discusses the mathematical notion of a Turing machine as a universally accepted formalization of the intuitive notion of a procedure
• Covers the general theory of computation, particularly computability and decidability

In short, this class represents a theoretically oriented treatment of formal languages and their models with a focus on their applications. It introduces all formalisms concerning them with enough rigor to make all results quite clear and valid. Every complicated mathematical passage is preceded by its intuitive explanation so that even the most complex parts of the class are easy to grasp. After taking this class, students should be able to understand the fundamental theory of formal languages and computation, write compilers, and confidently follow the most advanced books on the subject.

Knowledge of discrete mathematics.

• copy of lectures
• Meduna, A.: Automata and Languages. London, Springer, 2000.
• Meduna, A.: Elements of Compiler Design. New York, US, Tailor & Francis, 2008.
• Meduna, A.: Formal Languages and Computation. New York, Taylor & Francis, 2014.

• Parsons, T. W.: Introduction to Compiler Construction. Freeman, New York, 1992.

1. Formal languages.
2. Translation of languages and the structure of a compiler.
3. Regular languages and their models: regular expressions and finite automata.
4. Lexical analysis: lexical analyzer; Lex; symbol table.
5. Context-free languages and their models: context-free grammars and pushdown automata.
6. Syntax analysis: deterministic syntax analysis, FIRST and FOLLOW, LL grammars.
7. Deterministic top-down syntax analysis: recursive descent.
8. Deterministic bottom-up syntax analysis: simple precedence analysis; Yacc.
9. Semantic analysis and intermediate form generation.
10. Optimization.
11. Code generation.
12. Chomsky hierarchy and the corresponding models.
13. Remarks and summary. Preliminary discussion of the VYPe contents.

Students in teams (3 through 4 students per a team) implement a compiler/interpreter of a simple programming language (including a documentation).

There is a midterm test for 20 points without a spare or correction term. Students solve one team project during the semester (25 points) that is handed over before given deadline.

Final written examination (55 points): The minimal number of points which can be obtained from the final written examination is 20. Otherwise, no points will be assigned to a student.

In case of a serious obstacle (e.g. illness), the student should inform the faculty about that and subsequently provide the evidence of such an obstacle.

• The midterm test takes place approximately in the middle of the semester without a spare or correction term (20 points). If student cannot attend the midterm test, (s)he can ask to derive points from the evaluation of his/her first attempt of the final exam. To enter the final exam in this case, at least 12 points from project are required.
• To apply theoretical knowledge, students work on a team project (25 points). Continuously, the team leader checks the team's progress. In case of illness of the most team members, the team can ask the responsible teacher to extend the time for the project.
• Finally, there is a final exam with two correction terms (55 points).

To be allowed to take the final written exam, the student has to obtain 20 points during the semester; out of these 20 points, at least four points have to be obtained for the programming part of the project.