[thelambentonion]

Two potential counter-examples to your productive software claim:

Opaleye [0], an Arrow-based [1] DSL for Postgres SQL that allows the user to create type-safe, composable, and (generally) optimally fast SQL queries.

Halogen [2], a type-safe frontend framework for PureScript [3] that models view component interaction as an algebraic datatype containing query actions (among other fairly advanced concepts).

If someone is used to a certain level of abstraction, then the higher levels might seem unnecessary until they invest the time into learning them. The only thing unique to functional programming is that it has inherited a lot of terms from theory (profunctor, monad, algebra) rather than inventing friendlier ones.

[0] https://github.com/tomjaguarpaw/haskell-opaleye

[1] https://www.haskell.org/arrows/

[2] https://github.com/slamdata/purescript-halogen

[3] http://www.purescript.org

[pron]

> Two potential counter-examples to your productive software claim

How are those counterexamples? Do they provide benefits that significantly outweigh their cost?

> the higher levels might seem unnecessary until they invest the time into learning them

Except that this can't go on forever. Because we know that programming productivity has a theoretical upper bound, therefore there must be diminishing returns, and at some point the cost of more abstraction would outweigh the benefit. We just don't know where that point is. Finding out is not a matter of faith or even personal feeling, but of actual results.

Now, I know that collecting meaningful productivity data is hard, but that evidence of a claim is hard to come by doesn't make that evidence any less necessary for the claim. You're free to say that you like FP because you enjoy it more, or even that it makes you feel more productive. But you can't make actual empirical claims without actual evidence.

> The only thing unique to functional programming is that it has inherited a lot of terms from theory (profunctor, monad, algebra) rather than inventing friendlier ones.

I'm not entirely sure that's the case. FP is often its own theory. I'm not sure many of those concepts were studied heavily outside the context of FP, but I could be wrong about that.

[tel]

Profunctor and Monad are heavily studied in CT and many related mathematical fields that use category theory. For instance, algebraic geometry and logic. Algebra is incredibly well studied under the name "abstract algebra" and is one of the core concepts in modern mathematics since Bourbaki.

But this is just a side point to what you're saying.

[Illotus]

I don't understand why this doesn't have more votes. Asking for evidence is good, not bad. It isn't in any way self-evident that FP increases productivity. That's not to say that I don't like it, on the contrary.