CS118 Programming Languages

Lecture 6

Reference

• Chapter 2, 2.3-2.4, Fast Compilers (draft) McKeeman

Contents

1. Review Grammar Grammars
2. Top-down Parsing
3. Self-executing Grammars
4. GEM, deblanking, inverting, pretty printing...
5. Regular Expressions
6. Regular Expression Grammars
7. A Programming Problem
8. Assignments

Grammar-grammars (review)

...like self-printing programs

Top-down Parsing

...depends on where you are and what you see (lookahead)

Self-executing Grammars

...backtracking by decrementing pc (sewing machine algorithm)

GEM

...implementing self-execution

Regular expressions

...by themselves, and as a grammatical notation

Regular Expression Grammars

...getting some leverage

A Programming Problem

See the assignment.