I hope you're not suggesting that it's impossible to write this function without such constraints. If so, you should jettison your PL as fast as you can.

In any case this is precisely the trouble I believe the typer enthusiast get into. You can keep pulling this yarn, refining your types to match the world as it exists today; meanwhile the dynamic typers forgot about this function days ago and are eating your lunch in productivity.

> I hope you're not suggesting that it's impossible to write this function without such constraints.

To be concrete about it, that's exactly what I'm suggesting.

Please demonstrate, in any programming language, a derivative function that is parametrically polymorphic - that is, the same machine code will handle absolutely any type that's thrown at it - floating point, integral, string, function, map, set, graph, etc. I do not believe it's possible, unless you have some very different notion of derivative in mind. I would be delighted to learn it is possible, and mildly pleased to learn of a reasonable use of the phrase "derivative function" that's other than what I'm thinking and which makes sense of what you've written above.

Or... other people working in other languages you (obviously) don't understand have their own effective ways of working which you also don't understand.

It's a lesson that could be better understood by parts of the Haskell community, to be sure, but it's not always clear how useful a tool can be when you don't really know how to use it.

And here, you have repeatedly shown that you really don't know what you're talking about - take the opportunity to learn.