[jerf]

I'm not talking about using it when it's helpful. I do it myself all the time.

I'm talking about forcing it in when it hurts specifically.

It occurs to me that I may have accidentally answered myself at the end, when I referred to the concept of union vs. intersection. When you bring in helpful angles on your current paradigm from light cast by other paradigms, that's helpful. You're expanding your working set of options.

But when you get a bit of a good taste of those other paradigms, and then declare this is always the right way to do it, it may feel like you're expanding your paradigms, but now you're not. When you force sum types into a language that doesn't support them because they're just always the right answer, when you force lots of maps & filters in a language that can't do fusion and function calls are kind of expensive, when you force an algorithm in that depends on laziness to work, and so on, you are no longer working in a sort of union of paradigms. You're working in the intersection.

And that intersection sucks. A worst-of-both-worlds situation for sure.

You can tell, by the way people trying this are constantly screaming in pain about it.

When it hurts... stop.

[ImprobableTruth]

Sure, it's best to work with rather than against the language, but for most languages support of functional programming is not binary, just like with OOP.

I'm pretty sure most of the complaints are generally of the "This FP thing would work well here, but the language is unfortunately not quite there" nature rather than "I will try to implement profunctor optics in C no matter the cost" square peg in round hole crazyness.

>when you force lots of maps & filters in a language that can't do fusion and function calls are kind of expensive

I think that's perfect example to show that it's really about degrees, because fusion is really a Haskell thing. Sure, it's a nice-to-have, but it's definitely not essential to functional programming.

And when people want sum types (which aren't even really FP, ALGOL had them first!), it's often because the idiomatic alternative just kind of sucks for what they're doing. Trying to "implement" sum types in a language without support is nonsensical, but complaints about lacking them are pretty understandable I think.

[setr]

I’m pretty sure half the purpose of the article is to resolve the ambiguity: does it hurt because the paradigm is inelegant for this problem, or because I don’t know how to make it elegant?

Just stopping anytime you struggle is precisely how you learn nothing at all