Colin Bull
The real world consists of independent entities interacting through asynchronous exchanges of information. Programming languages that provide abstractions for asynchronous computations and agents are ideally suited for modeling real-world problems. This chapter introduces asynchronous workflows and agent-based concurrency in F#.
Programming in the functional style promotes a compositional approach to problem solving. The solution to a complex problem can be composed from the solution to simpler subproblems. Pure functions and immutable data structures are the fundamental building blocks used to implement solutions using this approach. Code written in this style is clear, concise, and easy to reason about.
Unfortunately, for any program to be useful, it also has to interact via side effects with the real world. Interactions with the real world involve coming to grips with functional programming’s so-called “awkward squad,” including I/O and concurrency. A challenge for any functional-first programming language is how to express computations that interact with the real world without compromising the benefits of the compositional approach to problem solving.