OriRoth

See also "Fling: a fluent API generator" by the same author https://github.com/OriRoth/fling

Maybe an example of how to compose HTML from multiple parts would also be great to have as an example (-> template engine).

There are examples in the paper https://dl.acm.org/doi/10.1145/3586057 (last section I think).

Exactly. Although, I would add that type level computations definitely can be used to perform useful metaprogramming tasks, such as embedding domain-specific languages or enforcing API protocols at compile time. I show some examples in my other papers. You can also check out my blog post: https://blog.sigplan.org/2021/03/02/fluent-api-practice-and-...

Yes, this is an obvious mistake. What you wrote is the right statement.