Continuation-passing style (CPS)

Continuation-passing style (CPS) is a programming technique used to preserve the state of a program’s execution when it is interrupted. In continuation-passing style, a function call stores the current state of the program in the continuation data structure and passes it back to the operating system or to another function that will later resume it.

CPS allows for more options for optimization. It can improve not only the speed of code execution but also its readability. It is especially useful in functional programming, where iterative tasks can be broken up into a set of function calls that can be easily reused. It is also valuable for asynchronous programming since check-points in the execution can be set up.

CPS is closely related to tail-call optimization and is compatible with many languages, including Scheme, Haskell, and JavaScript. The technique is best used within languages and frameworks that are designed for functional programming, as these are usually expected to be able to support CPS.

Additionally, CPS allows for better error-handling and debugging, as it preserves the stack and all the data points it contains before the interruption. The state of the program at the interruption can then be used to debug the code.

Overall, continuation-passing style is a powerful and effective technique that allows for better coding optimization and error-handling. It is useful in functional programming for breaking up tasks into function calls and can be applied to different languages.