> if there are literally billions of dollars in industry riding on writing efficient and correct software, and Haskell is such an obvious productivity win, why does it have a market share that rounds to zero?

The young economist looks down and sees a $20 bill on the street and says, “Hey, look a twenty-dollar bill!”

Without even looking, his older and wiser colleague replies, “Nonsense. If there had been a twenty-dollar lying on the street, someone would have already picked it up by now.”

Industry makes collective bad engineering decisions all the time, usually driven by secondary factors like institutional momentum or hiring constraints. Did you read the article? It talked about a bunch of things like that.

If you equate market cap with quality, then Java is probably the best language of all time.

> wrote a book on OCaml

I find it hard to believe that anyone who’s really used both prefers OCaml over Haskell. OCaml is nice compared to most crap, but as someone who’s spent years working with both, Haskell wins almost every time.

It’s interesting, actually - I don’t know anyone who’s used Haskell and doesn’t like it. Almost everyone who vocally complains about it hasn’t really used it.

Reading that guy’s reddit posts, I have to conclude he’s some kind of troll - most of the things he criticizes Haskell for are way worse in OCaml, or just completely disconnected from reality.

> if there are literally billions of dollars in industry riding on writing efficient and correct software, and Haskell is such an obvious productivity win, why does it have a market share that rounds to zero?

Well, one reason we might get stuck on a “suboptimal” language is network effects outside of the criteria we use to compare languages: what language does an organization already have experience with, does the (only) current compiler support the target hardware and system, it’s to late now to write the Linux kernel in Haskell, etc.

However, I agree with you. Despite the time I’ve invested in learning Haskell, I’ve personally decided to spend my time developing in other languages. If Haskell is the magic wand right there in front of us that will give us programs without flaws, how come almost nobody has picked it up and shown us working programs that took less development effort and fewer flaws.

We could compare John Wiegley’s ledger (C++) to the similar hledger (Haskell), but hledger isn’t the same program as ledger it has different features, I have no idea how long it took to write, how many flaws it has versus the original, how different the developer skills were, how much time and defects were saved by it being a redesign, etc. And these are small single developer efforts (now with numerous contributors). From everything I can gather, they are both excellent. So in this case there is no compelling advantage demonstrated for Haskell, and this supports your point.

Following links in your 1), I liked https://www.cs.hmc.edu/~oneill/papers/Sieve-JFP.pdf 'The Genuine Sieve of Eratosthenes' by Melissa E. O’Neill. Somewhat damning and to your point.

Are there any theoretical barriers to writing algorithms in a pure and lazy language with the same space/time complexity as a side-effectful and strict language? I suppose quicksort (also mentioned) is an obvious candidate for study in this regard.

I read those two links. If I ignore some of the points that were valid 10 years ago but not anymore (e.g., there's now stack), and if I ignore some of the personal anecdotes, I come away feeling like much of what is said is not necessarily wrong but is nevertheless an exceptionally negative take. I think you can make almost any tool sound broken and unusable if you use nasty enough and strong enough language about a few examples.

Also, there really is very little substance behind the actual language criticism. It's hard to make a blanket statement that typeclasses are "overkill"; they seem to be showing up all over the place in new languages. Similarly, type annotations are incredibly useful and are also showing up all over the place these days outside of Haskell-land. The point on non-strict evaluation is by far the strongest and most legitimate.

jdh30, the author of both comments, is a massive OCaml fanboy and Haskell hater. I've seen him try to take Haskell performance numbers and interpret them using the wrong units to make them look worse. I'd take anything that he says about Haskell with a big, big grain of salt!

> Haskell is best at solving problems that Haskell invented and other languages do not have.

That is the most succinct explanation I've ever seen of Haskell.