Optics
Optics are a functional programming concept that provide a composable way to access, modify, and traverse nested data structures, such as records or objects, in a type-safe manner. They abstract over common operations like getting, setting, and updating fields, making code more modular and less error-prone when dealing with complex data. Originating in Haskell and popularized in languages like Scala and PureScript, optics include types like lenses, prisms, traversals, and isomorphisms.
Developers should learn optics when working in functional programming languages or projects that heavily use immutable data structures, as they simplify complex data transformations and reduce boilerplate code. They are particularly useful in scenarios like state management in UI frameworks, configuration handling, or data validation, where nested data needs frequent updates without mutating the original structure. Optics enhance code readability and maintainability by providing a consistent, composable API for data manipulation.