type system – Sven Hübner IT

Fun with generics: mapping a generic instance from a non-generic reference

By sven.huebner.it March 5, 2023General Development

DDD can lead to dealing with non-generic references to generic instances of types. Generically mapping these instances or generically calling code with them is not straightforward. I present how it can nonetheless be unobtrusively achieved with a general visitor-like pattern.

Fun with generics: building a generic call without reflection

By sven.huebner.it November 12, 2022General Development

DDD can lead to generic types that are hard to import to. This technique can be used to make a generic call with multiple type arguments when each type argument is supplied individually, e. g. from an import into a domain model.

Closed Type Hierarchies with records … NOT!

By sven.huebner.it February 23, 2022General Development1 Comment

TL;DR: You cannot create closed type hierarchies with record types because of the generated protected copy constructor.

Domain Primitives II: forcing developers to deal with error cases

By sven.huebner.it December 11, 2020General Development

Using a static method with a Result return type for creating domain primitives forces developers to deal with error cases.

My Take On Domain Primitives

By sven.huebner.it November 4, 2020General Development2 Comments

Domain Primitives are a stand-alone low-risk way to incrementally fortify your application, without the risk and complexity of introducing concepts like DDD, algebraic data types or immutability.