Hello, List! This is a little bit theoretical question but not only... Let's suppose I have a lot of functions like: llfunc :: A -> B -> C -> D -> C and I have types C and HLC and "constructor" of HLC from C: makeHLC :: C -> Maybe HLC -- or Either String HLC and I want to create "automatically" (i.e. with minimal coding!) functions like: hlfunc :: A -> B -> HLC -> D -> HLC -- see llfunc i.e. for each ll* (low-level) to create hl* (high-level). For example, I can have even HLC -> C function. I may have a lot of llfunc's. Idea is to replace a coding of hlfunc's with some automatically or semi-automatically deduce/creating of them. For example, C may be `FilePath`, HLC may be some kind of `Path a` (wrapper for paths). And I have a lot of FilePath-based legacy functions. I suppose it's possible to solve such problem in D language (I made somthing similar several years ago). And possible it's easy in Nim (Nimrod) because of them: a) types exist b) meta-programming features. IMHO should be a way to do similar in Haskell, but it does not look easy. IMHO I can code arguments + return types with Generic, and next step may be type class with custom methods C -> HLC/HLC -> C and default method like `perform` which will get Generic and automatically makes instance of this type class or... And how will it look like? Is it even possible in Haskell? === Best regards, Paul