Exhaustive pattern matching in Harbour - a working prototype

[Diego Pego]

Hey! I’ve put together a prototype for exhaustive pattern matching in Harbour, using pure Harbour and PP pragmas. The main idea is to have the compiler raise an error when a match (currently syntactic sugar for DO CASE) doesn't cover all possible cases for a given type.

You can check it out here:
https://github.com/diegopego/harbour-core/tree/master/contrib/diego

If you’re not familiar with exhaustive pattern matching, it ensures that all possible cases are handled explicitly at compile time. For a quick overview, these links give good context:

• https://medium.com/technogise/type-safe-and-exhaustive-switch-statements-aka-pattern-matching-in-typescript-e3febd433a7a

• https://fsharpforfunandprofit.com/posts/correctness-exhaustive-pattern-matching/

I’d love to hear your thoughts and feedback!