Introduction to Type Systems and Haskell GADTs

Understanding how compiler types work is the key to writing robust, bug-free software. If you want to move beyond basic programming and write highly reliable code, mastering type systems is the logical next step. This written course guides you through the core concepts of type theory, starting with foundational definitions and moving into the powerful type system of Haskell. You will learn how to leverage types to prevent runtime errors and design expressive APIs using advanced features like Generalized Algebraic Data Types (GADTs). What you'll learn: 1. Understand the core concepts and terminology of static and dynamic type systems. 2. Master Haskell's type system including algebraic data types (ADTs) and type variables. 3. Apply Generalized Algebraic Data Types (GADTs) to enforce domain invariants at compile time. 4. Practice type-driven development techniques to eliminate invalid states. 5. Explore modern type safety patterns and how they translate to real-world software design. The course begins with essential terminology and the theory behind type systems, then shifts to practical Haskell implementations, culminating in advanced type modeling with GADTs. This course is designed for programmers who are new to type theory and want to understand functional type systems, with no advanced mathematical background required. Start reading today to elevate your programming with the power of robust type systems.