Real-World Functional Programming

Chapter 15. Creating composable functional libraries

This chapter covers

• Designing functional combinator libraries
• Working with time-varying values
• Composing time-varying values with drawings
• Developing library for modeling financial contracts

A design principle that arises in many aspects of functional programming is compositionality. This means building complex structures from a few primitives using composition operations. We’re describing compositionality in a general sense because it can appear in countless forms. Let’s look at two examples you’re already familiar with.

We’ll begin with the F# type system: there are a few primitive types, such as integer and Boolean, as well as ways of combining them, such as using the * type constructor ...