Tutorial to grasp the rational behind union-types

[karlhp]

Does anyone know a good tutorial to grasp the rational behind union-types so that I understand the problem they solve? I know basic functional programming with Ramda but would like to learn more about functional-frontend-architecture with flyd.
Thanks

[ericgj]

In terms of "functional-frontend-architecture", AKA the Elm Architecture, check out this section of the Elm guide. The syntax is different but the concepts are the same.

A more general tutorial I found useful, particularly coming from OOP: A functional approach to Domain Driven Design. It's F#, so again the syntax is different, but many of the concepts are the same. The bit about union and product types starts around slide 49.

[karlhp]

Thanks @ericgj, this is very helpful!

[igat64]

Great article about sum (a.k.a. tagged or discriminated unions) types.

[brucou]

https://medium.com/fullstack-academy/better-js-cases-with-sum-types-92876e48fd9f