[supersillyus]

My "ah ha" moment with Haskell was after a few years of using it quite regularly, I realized that it wasn't actually making me more productive in the kind of code I actually write from day-to-day. It's a lovely language and I wouldn't discourage anyone from using it, but for my purposes I realized it was more exciting than useful at some point, and after that I haven't been back to it as much.

[CoffeeDregs]

Agreed. It's so beautiful, but so constraining. I'm a much better developer for having used it, but returned to Python/Ruby/Java[for-speed] after spending lots of time with Haskell.

That said, I desperately miss static-typing and Hindley-Milner type inference... I keep searching for the perfect language.

[srean]

Then I would be interested about your opinion on OcaML/MLTon, F# and Scala. To me they seem like a good balance. If you are more adventurous then try Felix.

EDIT: apparently someone did not like your comment. Some downvotes confound me.

[CoffeeDregs]

Would that downvotes interested me...

To your questions:

OcaML: seems like a hack-ish [S]ML. There's a nice comparison between SML and OcaML here : http://adam.chlipala.net/mlcomp/ . I like SML's syntax, but OcaML made it too easy to be imperative and seemed too hackish. Most of the OcaML I've seen looks like weird C, but written in OcaML because it's F4ST3R.

F# : I run Linux... next!

Scala* : I can't stand it. I use Python for everyday coding and I really don't like the philosophy behind str(), len(), and friends, but it's otherwise straightforward. There's pretty much only 1 [reasonable] way to do things in Python. Scala seems like the evile lovechild of Perl and SML. Classes and "case Classes"? WTF? Type inferencing, but not powerful type inference? If you're going to move to Java++ without going too far toward Haskell, then Gosu or Mirah seem like better compromises. That said, I'm only investigated Scala [not coded in it], so my griefing is likely due to a lack of familiarity.

SML/MLTon: the syntax is 95% good but they should have embraced significant-whitespace wholeheartedly. Do they really need an "end"? But, generally, I really like SML's thinking. In particular, I'm rooting for SML by following Yeti (https://github.com/mth/yeti; but "case" is closed with "esac", really?!) and Roy (http://roy.brianmckenna.org/). Oh and I hate header files. Sooooo 1995...

Clojure: static typing. I want to believe, but the lack of static typing (including Hindley-Mindler type systems) seems like a short-cut. I think the static/dynamic typing argument is a relic of pre-good-static-typing system and I don't think that big, server-side languages should be dynamically and/or weakly typed. That said, Stuart, and his hair, are great.

Felix: interesting, but I see no mention of type inference, so have concerns about the type system. Also, the wiki is broken and that makes me think "dead project".

But, unfortunately, I want mature toolchains, libraries, etc, so, though I wrote a mid-sized web framework in Haskell, I'm one of those who is waiting for a functional language to emerge as the winner. Until then, I'll work in Python and will support Yeti and Roy.

* I've forgotten where I saw it, but Scala also had some bizarre rules around interpreting variables in case statements [or something] involving the case of the argument. I closed the book at that point. Haskell has special notations for special features, not special assumptions for normal features.

[bad_user]

     [Scala] Type inferencing, but not powerful type inference?

In Scala the Hindley–Milner type inferencing is not possible because Scala is OOP, compared to Haskell which isn't.

Ocaml does have Hindley-Milner, but not for the OOP features and whenever I played with Ocaml it felt like 2 different type-systems shoved into the same language (much like Obj-C). Scala on the other hand is more consistent, elegant and simpler. That's why it has "case classes", because case classes are used for algebraic data-types, which have special properties that aren't necessarily shared by normal classes.

And because of implicits, the type-system is also more powerful than what's available in Ocaml and even Haskell. It's arguably too powerful, but the things that the collections library can do have no match in other languages. E.g. http://stackoverflow.com/a/1728140/3280

I also liked to bitch and moan about the lack of real type inferencing in Scala, however in Ocaml and Haskell just because the types are not specified, that doesn't mean you can ignore those types. Quite the contrary, you always have to be aware of those types, as opposed to working in a dynamic language. That's why it's standard practice in Haskell to add those types explicitly for public APIs, because otherwise it hurts readability a lot.

[dons]

> And because of implicits, the type-system is also more powerful than what's available in Ocaml and even Haskell.

I don't think that's true. You do the same thing (e.g. collections that choose better representations) via type families/associated data types in Haskell. E.g. in [1] or [2]

That said, what is true is that Odersky has modified the Scala type system in quite interesting ways, specifically to support his collections library. [3]

[1]: http://hackage.haskell.org/package/adaptive-containers

[2]: http://hackage.haskell.org/package/accelerate

[3]: http://lampwww.epfl.ch/~odersky/papers/fsttcs09.html

[srean]

> F# : I run Linux... next!

I feel your pain. The other thing that bothers me is that Mono developer(s?) have been extremely bone headed about tail recursion. Hey guys if you are reading this, sorry about the tone, but that needed saying. John Harrop can be quite a troll but he is right in calling Mono out on this. Their incorporations of futures and promises is indeed an attraction though. But then we only have a non-binding promise from Microsoft that they wont go after other implementations. Thats not a threat I would like to be under.

I really would love a multicore enable runtime for OCaML. I dont even ask for threads, just the ability to run some of the concurrency exposed by the functional semantics be (optionally) run in parallel without forking processes.

Yeti...I dont know, unless JVM includes proper tail calls I will always have this nagging sensation in my brain.

Felix, BTW is far from dead, in fact it is quite the opposite, its too intensively developed. The wiki is very new, so there would be some breakage there. The original website is stable. Oh it uses Hindley-Milner type inferencing.

From your comment it seems you would like the white space thing http://people.csail.mit.edu/mikelin/ocaml+twt/ I have never used it though.

Wonder if there is anything akin to P4Caml for SML to give you significant white space. But I think you will get over the syntax :) I have to work with arrays a lot, there SML is a bit more verbose.

[halter73]

Where do you get the impression that Microsoft's promise is non-binding?

Microsoft's official FAQ on their Community Promise explicitly states that it irrevocable and legally binding [1]. I have previously read complaints that the promise doesn't cover enough of the .NET libraries among other issues [2], but I was not aware until now of anyone claiming that it is non-binding.

[1] http://www.microsoft.com/openspecifications/en/us/programs/c...

[2] http://www.fsf.org/news/2009-07-mscp-mono

[mahmud]

I don't think you understand either ML or Lisp. SML would never make whitespace significant because: 1) that's a brain-dead choice, and 2) ML, much like Lisp, is used as a language, as a notation, and as a "kernel" language.

Clojure without dynamic-typing is bath-water without baby. What is the point of interactivity, homoiconicity and macros if the language is statically typed?

[dllthomas]

> What is the point of interactivity, homoiconicity and macros if the language is statically typed?

If the type system can handle it? MAGIC!

[hencq]

Is there any specific reason why macros can't work in a statically typed language? How does Typed Racket handle this. Or does it not have macros?

[heretohelp]

Typed Racket is more like type annotations with a checking routine than anything, if you're writing a macro you want generality.

You achieve this by omitting the type annotation and reverting to normal Racket.

You can do macros in a statically typed language, but it would (and does) get ugly fast.

[swah]

Why do you say "whitespace is a brain-dead choice" ?

[morsch]

I'm sure any downvotes he got (I didn't moderate) was due to his making a fairly strong, and fairly objective claim -- Haskell is constraining -- without saying why it was constraining or even elaborating in what manner it was constraining.

[pka]

Could you give a concrete example that shows why Haskell is constraining?

[masklinn]

> I realized that it wasn't actually making me more productive in the kind of code I actually write from day-to-day

I've got a quip for that in my quotefile:

> "Haskell mainly helps with my C++ template coding when I'm doing money oriented programming" -- fnord123

[jerf]

I've noticed that slowly, but surely, Haskell really is winning. C++ is now basically running as fast as it can to become Haskell. It's such an old language with so much baggage that "as fast as it can" isn't very fast at all, and it has no chance of ever reaching it, but the trendline is clear.

The question the programming community faces over the next, oh, ten years or so, is "Can we get the benefits of Haskell without the strict attention to the type system and without having to rigidly separate IO?" Or a bit more sarcastically/cynically, can we get the benefits without having to fundamentally change how we do business? My gut says no, but I'm open to being proved wrong. (Oh, and yeah that's not the only question, there's others like "What about OO? Can we keep it?", but I think that's really the core question; do we really have to rigidly control our side effects or can we keep our sloppy side-effect usage? Everything else is either incidental next to that, or flows from it.)

[sseveran]

The answer is no. Marking side effects is the one thing, probably more than any other that makes haskell awesome for building applications. For instance STM is awesome in Haskell because it is easy for the compiler to see any and all side effects.

The real thing that would be cool would be a strict haskell with optional laziness.

[jerf]

As I said, my gut agrees with you, but I think that given the relative newness of this idea, that the programming community at large should be given some time to make the case that the benefits can be obtained without so much of the cost. There's only a bare handful of languages that have even taken a serious swing at it, like Clojure and lately D. I want more evidence before I call it.

Probably the most promising approach that might salvage conventional programming approaches is a process-based model like Erlang or Go, where each process is internally mutable (mostly unlike Erlang, though it does have the process dictionary), but strictly segmented such that one process can not mutate another's state. This hybrid approach might be viable, and while it's not exactly business-as-usual, it's not as far a trip as full-on IO isolation. (Still, that affords just slamming everything in one process, at which point you don't win much. Will be interesting to watch Go's ecosystem develop and see if goroutines manage to become something deeply and pervasively used in all libraries or a thing occasionally used when the situation is desparate.)

[masklinn]

> mostly unlike Erlang, though it does have the process dictionary

Yes and no, while Erlang structures are not mutable (aside from the process dictionary, and the process's message queue), each new iteration of the process loop mutates the process itself, as the process goes from one state to an other.

[jerf]

Erlang values are not mutable. You can't have a 4, lose the execution pointer to another process, and when it comes back you suddenly have a 5 in that variable. (Barring arbitrary C, of course.) That's the aspect of "immutable" that matters from a multithreading point of view. For most of what Erlang does, it would be fine to have mutable variables but immutable values, as if everything were as immutable as a Python string but you could freely reuse variable labels just as you can set a = "A", then a = "B" in Python. I think that's basically what Go does, though I haven't quite studied it enough to be sure.

[pka]

For all my love of Clojure, having used its STM implementation I can wholeheartedly agree with this.

Having side effects in a transaction occur more than once because you didn't pay attention is a real pain to debug, mostly because the transaction won't be retried until the program is exposed to heavy load leading to serious memory contention.

At that point, debugging concurrent designs turns into a nightmare, not being any better than having to deal with deadlocks etc, the very thing STM is supposed to magically make go away. In some cases I even had to resort to locks because it was easier to handle IO that way.

Now, Haskell's type system would just not allow having any sort of IO side effects inside a STM transaction. Yes, having to explicitly handle IO may sound as a lot of work, but in my experience it makes everything easier.

[slewis]

What's your go to language now?

[wardenclyffe]

I trust that you've read the excellent essay "And then there's Haskell..."

http://www.xent.com/pipermail/fork/Week-of-Mon-20070219/0441...

(Edit: After further research if you were on Hacker news mid january last year this would in fact be old news, sorry for the unwitting repost)