Get Programming with F#

Unit 5. The pit of success with the F# type system

We’re making progress now! We’ve covered F# syntax, FP principles, functions, and collections—almost there! This next unit is the last one to focus on core language features in F#—remember that this book covers a core subset of the F# language, after which you’ll have some fun writing meaningful applications that use a variety of frameworks and libraries.

A common phrase you’ll hear in F# circles is the ability to “make illegal states unrepresentable.” In C# and VB .NET, we’re used to the notion of proving that an application is correct through, for example, unit tests and console applications. In F#, we still use unit tests, but to a far smaller degree. Part of that, as you know, is because ...