Principles, techniques, and tools[1] is a computer science textbook by alfred v Lam, ravi sethi, and jeffrey d Ullman about compiler construction for programming languages First published in 1986, it is widely regarded as the classic definitive compiler technology text [2] it is known as the dragon book to generations of computer scientists [3][4] as its cover. The ast is used intensively during semantic analysis, where the compiler checks for correct usage of the elements of the program and the language
The compiler also generates symbol tables based on the ast during semantic analysis A complete traversal of the tree allows verification of the correctness of the program. Principles of compiler design, by alfred aho and jeffrey ullman, is a classic textbook on compilers for computer programming languages Both of the authors won the 2020 turing award for their work on compilers. Design requirements include rigorously defined interfaces both internally between compiler components and externally. Thus in the hack, the lexer calls the semantic analyzer (say, symbol table) and checks if the sequence requires a typedef name
