book Crafting Interpreters programming language compiler

Chapter 5 - Representing Code

Context-Free Grammars

Rules for grammars

• Rules are used to generate strings in the grammar
  • Strings are derivations (derived from the rules)
• Called productions (produce strings)
• Productions have:
  • Head
    • Its name
  • Body
    • Describes what it generates

Visitor pattern

• Design pattern
• Used to help minimize the pain from the expression problem
• Build out a class (PastryVisitor) that has specific visit methods for each subclass of the thing you are visiting