Formal Languages and Compilers

This course discusses formal languages and their models. Based on these models, it explains the construction of compilers. The lectures are organized as follows: (I) Basic notions: formal languages and their models, grammars, automata; compilers. (II) Regular languages and lexical analysis: regular languages and expressions, finite automata and transducers, lexical analyzer; Lex; symbol table. (III) Context-free languages and syntax analysis: context-free grammars, pushdown automata and transducers, deterministic top-down syntax analysis (recursive descent), the essence of deterministic bottom-up syntax analysis; Yacc. (IV) Semantic analysis and code generation: semantic checks, intermediate code generation, optimization, code generation.

Links

• Public website of IFJ (private part offers lecture slides (both CZ and EN) and supporting materials for the project)
• E-learning website for WS 2024/25 (Moodle, private, only in Czech) supporting the project (forum) and providing additional materials

Why is the course taught

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.

Exam prerequisites

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 4 points have to be obtained for the programming part of the project.