Algebraic Data Types
Algebraic Data Types (ADTs) are a type system concept in functional programming that allow the definition of composite types through algebraic operations, primarily sum types (disjoint unions) and product types (tuples or records). They enable the creation of complex data structures by combining simpler types in a type-safe manner, often used to model domain data with precise constraints. ADTs are foundational in languages like Haskell, OCaml, and Scala, and are increasingly adopted in mainstream languages like TypeScript and Rust.
Developers should learn ADTs to write more robust, maintainable, and type-safe code, especially when modeling complex data domains such as state machines, ASTs, or business logic with multiple variants. They are essential for functional programming paradigms, reducing runtime errors by encoding invariants at compile-time, and are widely used in areas like compiler design, data validation, and API design. In modern software, ADTs help prevent bugs by making illegal states unrepresentable, improving code clarity and reliability.