What This Document Is
These are lecture slides from CS 781: Compiler Design and Construction II at Wright State University, focusing on the critical phase of type checking within the Cool language. The material delves into the formal systems used to verify the correctness of programs, moving beyond grammar and regular expressions to explore logical rules of inference. It establishes a foundation for understanding how compilers ensure that operations are performed on compatible data types, preventing runtime errors and ensuring program reliability.
Why This Document Matters
This resource is invaluable for students enrolled in advanced compiler design courses, particularly those working with statically-typed languages. It’s most beneficial when you’re grappling with the theoretical underpinnings of type systems, attempting to formalize type checking procedures, or needing a deeper understanding of how compilers enforce type safety. It will be particularly helpful when you are tasked with implementing a type checker for a programming language. Understanding these concepts is crucial for building robust and dependable software.
Common Limitations or Challenges
These slides present a theoretical framework. They do *not* provide a step-by-step guide to implementing a type checker in a specific programming language. The material assumes a solid foundation in compiler theory, formal languages, and basic logic. It also doesn’t include practical code examples or debugging strategies. It focuses on the *why* and *how* of type checking at a conceptual level, rather than the *how-to* of implementation.
What This Document Provides
* An overview of core type concepts within the Cool language.
* A formalized notation for expressing type rules using logical inference.
* Exploration of the properties of sound type systems.
* Illustrative examples transitioning from English descriptions to formal inference rules.
* Discussion of type environments and their role in managing variable types.
* An introduction to the challenges of type checking, such as handling variable references.
* A framework for constructing type checking proofs based on the Abstract Syntax Tree (AST).
