Regular Expressions and Lexer Idea

This lecture covers the concept of regular expressions, starting with defining languages using properties and regular expressions. It delves into the history of regular expressions, including the work of Stephen Cole Kleene. The lecture explains the different operators and operations involved in regular expressions, such as union, concatenation, and Kleene star. It also discusses lexical analysis, the construction of lexical analyzers using regular expressions, and the automation of this process. The lecture concludes with examples of manually constructing lexers and recognizing identifiers and keywords.