State of the Haskell ecosystem

https://github.com/Gabriel439/post-rfc/blob/master/sotu.md

by boothead • 11 years ago

148 71 11 years ago

Thanks for this. A couple of points:

1: I'd have rated Haskell's concurrency as "best in class" thanks to its STM implementation. Other languages do have STM, but AFIAK only Haskell provides both efficiency and safety thanks to its type system. Other languages have to choose between tracking every variable (slow) and letting the programmer declare which values are going to be rewound if the transaction aborts (unsafe).

2: Your section on IDEs does not consider Leksah. I've just come back to this after a long time on Eclipse and Atom, and its now a mature IDE specialized for Haskell. You might consider bumping Haskell to "mature" based on this.

boothead4• 11 years ago

Great to hear that Leksah is coming along. I'm a happy emacs user, but I think a good IDE environment can only help adoption.

cies2• 11 years ago

I agree on concurrency. It is best in class and also offers a lot of choice (which some other popular languages like JS and Go are not providing).

When it comes to IDEs I do think immature would also be my choice. There is a lot of movement on this front so I have hopes this may change soon. My main points are: 7.10 is out for a while but most editor integrations have/had (until recently) some major issues with it. Also Stack is bocoming quite popular, yet most editor integrations are not Stack-aware. Finally the editor integrations are not much plug-and-play. As said, this is changing rapidly with some necessary fixes to GHC/cabal made and projects like stack-ide and ghci-ng.

hamishmack2• 11 years ago

When it comes to IDEs I do think immature would also be my choice.

If you have not already logged any issues, can you please list the top few things that bugged you about Leksah here and I will make sure they get added to the issue tracker? Even if they are already there it will help us prioritise to know what your pain points were.

Thanks

srtjstjsj2• 11 years ago

2: Your section on IDEs does not consider Leksah. I've just come back to this after a long time on Eclipse and Atom, and its now a mature IDE specialized for Haskell. You might consider bumping Haskell to "mature" based on this.

On a recent thread on Reddit, the Leksah maintainer acknowledged that on some platform (I forget which), Leksah crashes in every session, and has a CPU-spinning bug.

hamishmack2• 11 years ago

the Leksah maintainer acknowledged that on some platform (I forget which), Leksah crashes in every session

Only on exit, so it has not been a high priority to fix.

https://github.com/leksah/leksah/issues/130

and has a CPU-spinning bug.

This was in version 0.15.1.0, 0.15.1.1 and 0.15.1.2. It was fixed in 0.15.1.3 (released a month after 0.15.1.0).

https://github.com/leksah/leksah/issues/149

Please try Leksah! It is not perfect, but any feedback you could give would help us make it better.

radmuzom• 11 years ago

This is a great and a balanced list. I have definitely enjoyed some time spent programming in Haskell.

One frustration that I have had while dabbling in Haskell is that some libraries in Hackage assume a GNU/Linux kind of system. For example, I was reading Simon Marlow's book and while trying to compile the examples in a Windows machine, a particular library could not be installed because of the lack of 'configure' (GNU autotools? I only use Windows nowadays due to professional reasons and have not used GNU/Linux last 11 years). I hope that library authors do not make such assumptions unless it really necessary.

Is there an opportunity for a company to create an implementation of Haskell which fixes some commonly mentioned problems (e.g. stop the world GC) - like proprietary JVM vendors? Is it even technically feasible? Of course, such a hypothetical company would also need to spend a lot of time writing useful libraries.

cies2• 11 years ago

I've heard the GHC on Windows situation improved a lot with:

https://github.com/fpco/minghc

Myself I don't use Windows, so verify the claims. But might be worth to give it another try.

Also Stack[1] has made it lots easier to get rolling on that platform.

1: https://github.com/commercialhaskell/stack

Myrmornis• 11 years ago

I don't mean to trivialize the complexities and importance of setting up a development environment you are happy with, but Linux is very easily available to a Windows user via virtualbox VMs or boot2docker. Are you sure you can't find a workflow involving those that you're happy with? Editing files doesn't have to use an editor in the VM.

erose12• 11 years ago

Do you mind explaining what a natural workflow for this would look like? Is it to SSH into the VM using your editor of choice?

kryptiskt2• 11 years ago

I'm a Haskell Windows user (and an Idris developer), and I have little trouble installing most things (except those directly targeted at Linux). That's not because I'm awesome, but because there's a trick to it. The trick is to install msys2 (https://msys2.github.io), and do the installs from there. Set up its libs and include as extra dirs in Cabal's config. When you need some lib or build tool look for it with pacman -Ss and install it. To start with installing make and autoconf helps you over the configure hurdle.

And if you hit Cabal hell now and then, that happens to everybody so it's probably not because you're on Windows, just make a sandbox and see if it works there.

kryptiskt2• 11 years ago

My Idris installation instructions: https://github.com/idris-lang/Idris-dev/wiki/Idris-on-Window...

It's an example of pulling down build tools and libs (well, a lib) with msys2.

QuantumRoar3• 11 years ago

For me, it was (and still is) terribly hard to find libraries that do what I want. Although Hackage has a large database, it's quite confusing and very hard to figure out how a library actually works.

A few years ago, I tried to parse HTML files for a very small thing that I wanted to do and I just couldn't find or understand whether there's actually something out there that I could use. So, instead, I ended up learning Parsec and writing my own crappy parser...

I really don't think that's what it should be like. And maybe it's just my own fault. If not, there should be thousands out there who start their Haskell journey with such a frustrating experience. There's a deep and dark abyss in which beginners fall after an initial tutorial.

I've never had a similar experience with any other language. The upside, of course, is that Haskell is the most beautiful language I know.

boothead4• 11 years ago

I think this is because the abstractions are so abstract. When functionality is glued together with very general combinators and operators there's not really much to grab hold of unless you understand the abstractions.

QuantumRoar3• 11 years ago

Well said. What always saved me is that brave and devoted individuals wrote tutorials and published them to help me peel away the layers of abstractions. There's no way I could have done that on my own.

Symmetry• 11 years ago

Sometimes, but sometimes a function just has a type of String -> String with nothing besides the name to tell you what it does.

lallysingh• 11 years ago

Google is your friend: "html scraping Haskell" -> https://hackage.haskell.org/package/scalpel

Googling is the best way to go through hackage.

QuantumRoar3• 11 years ago

I know that. The situation got better in recent years. I was trying to point out that as a beginner, it is really hard to find your way and I still think it is. I learned Parsec and solved my problem that way since I could find an okay-ish tutorial for that. If at that time I had found a TagSoup tutorial, I would have probably used that.

It is sometimes hard to grasp how it is to not know something. As a beginner, you don't just write down your Monads and Monad Transformers. You don't just read the source code of libraries on Hackage. You need a lot of guidance.

mb2100• 11 years ago

Google "haskell parse html", the first hit is a tutorial, the second hit the TagSoup library on hackage.

gsnedders2• 11 years ago

TagSoup is pretty poor — it's far from being an HTML parser (as defined by the HTML spec). The big problem is that because it's really just a tokenizer, it doesn't do any of the handling of mis-matched tags, which is really the interesting part of parsing HTML. Even insofar as what HTML can be parsed by a streaming parser, it's not great, as it doesn't imply any tags (which are a big part of HTML!).

It does, in its own code, state:

    -- We make some generalisations:
    -- <!name is a valid tag start closed by >
    -- <?name is a valid tag start closed by ?>
    -- </!name> is a valid closing tag
    -- </?name> is a valid closing tag
    -- <a "foo"> is a valid tag attibute in ! and ?, i.e missing an attribute name
    -- We also don't do lowercase conversion
    -- Entities are handled without a list of known entity names
    -- We don't have RCData, CData or Escape modes (only effects dat and tagOpen)

All of which mean that it doesn't actually follow what the HTML spec says! Just because it claims to support the spec doesn't mean much!

zeckalpha3• 11 years ago

You may be interested in Hayoo: http://hayoo.fh-wedel.de/?query=Html

Unlike Hoogle (which only searches a few things) Hayoo searches most of Hackage.

tel2• 11 years ago

For ML and Data Science I'd say very immature. HLearn does interesting things but is far from providing a workable ML or Data Science workflow. We need solid, unquestionable Matrix and Vector libs upon which the ~50 bread and butter algorithms cans be solidly implemented. Then Diagrams needs super tight integration and connections to "big data" systems can be built. Frames is moving in the right direction type-wise but it'd be really nice to get HLists (or even vinyl?) in as representations which can be transparently backed by the aforementioned common matrix libs. Lenses could probably help a lot here and I think Anthony is going in that direction exactly.

Neatly, the GPU story is actually quite strong and could be integrated with this hypothetical ML and Data Science platform I'm describing quite nicely. That'd be a not small boost to its power.

jordigh• 11 years ago

What's the difference between ML and data science? ML has more programming?

And what's the difference between data science and statistics? Statisticians try to come up with new mathematics, while data scientists just try to come up with ways to apply that maths?

tel2• 11 years ago

I'll take a brief stab since I think there are important differences but this is also holy war territory so YMMV.

ML tends to be more concerned with scale and computational efficiency as the algorithms used are often (a) heavyweight and (b) less human interpretable. Success is primarily measured objectively but via proxy measures like prediction accuracy. It may require data science efforts behind the scenes in order to succeed.

Data Science tends to be more concerned with interpretation than scale or repetition. It sits somewhere between analyst, sataistician, and journalist. It's also a much more interactive workflow often involving a great deal or successive, simple models and lots of exploratory visualization. Measures of success include discovery of human-relatable inferences from data, substantiation or dismissal of human-relevant experimental hypotheses, and success in communication of those ideas.

Statistics is a field of study of some of the most important mathematical foundations of each of these roles. A statisicians skill is more generalized but also more abstract. A statistician who learns CS and journalism could easily head into either other field.

sklogic13• 11 years ago

Haskell is an amazing language for writing your own compiler. If you are writing a compiler in another language you should genuinely consider switching.

Uhm, no, thank you, but no. Haskell is poorly equipped for implementing compilers, because of its lack of unrestricted compile-time metaprogramming.

I'm spoiled. This is what I want from a language for implementing compilers:

1) Cheap, boilerplate-free definition for chains of slightly different ASTs and IRs. Haskell and ML are notoriously weak in this area (see the "Expression Problem" thing)

2) Boilerplate-free generation of various (potentially complex) visitors for these ASTs and IRs. For Haskell, Scrap Your Boilerplate library is the closest thing to what I want, but it is still far too clumsy.

3) I need efficient embedded Prolog and Datalog (yes, both, the latter allows some cool optimisations not possible for the former). Not feasible without compile-time metaprogramming. Both are important for simplifying compiler construction.

4) Parsing is not very important. But yet, it is necessary. The best Haskell got on offer is Parsec. Sorry, not good enough for my requirements.

fs111• 11 years ago

Out of curiosity, what language, if any, has those properties?

sklogic13• 11 years ago

Any language that allows compile-time metaprogramming (and not as restricted as TH) should allow to implement all the components I want. One example of such a system is the Nanopass framework [1], used alongside with cKanren [2].

Another example is my own system [3].

[1] https://github.com/akeep/nanopass-framework http://www.cs.indiana.edu/~dyb/pubs/nano-jfp.pdf

[2] http://scheme2011.ucombinator.org/papers/Alvis2011.pdf

[3] https://github.com/combinatorylogic/mbase

jberryman• 11 years ago

What are your parsing requirements?

sklogic13• 11 years ago

Pretty basic: graceful error recovery, arbitrarily complex error reporting, arbitrary actions (potentially with some side effects). I.e., everything that is needed for the IDE integration and for the professional compiler frontends with usable, friendly error messages and recovery suggestions.

coldtea5• 11 years ago

So "Haskell is poorly equipped for implementing compilers" because it doesn't fit your bizarro requirements, including "efficient embedded Prolog and Datalog"...

sklogic13• 11 years ago

Haskell is poorly equipped for implementing compilers because writing compilers in Haskell requires tons of boilerplate, which is not needed in the languages that are a much better fit for this task. Kinda obvious from a definition of what "poorly equipped" means.

And why do you call these basic requirements bizarre? For example, something like a region inference is just a few lines of Prolog vs. dozens or even hundreds of lines of code in Haskell.

zeckalpha3• 11 years ago

2) Boilerplate-free generation of various (potentially complex) visitors for these ASTs and IRs. For Haskell, Scrap Your Boilerplate library is the closest thing to what I want, but it is still far too clumsy.

Have you tried QuickCheck?

4) Parsing is not very important. But yet, it is necessary. The best Haskell got on offer is Parsec. Sorry, not good enough for my requirements.

I've not found much better than (atto-)Parsec, to the point where I miss it in other languages.

protomyth• 11 years ago

Although hinted at in "Mobile apps" and "Package management", I think you might want to add "Deployment" to your list of criteria for a language. It is often overlooked with languages and frameworks, but the ability and method of deploying code (particularly with a running system) should not be ignored.

reflexer• 11 years ago

I think the rating difference between sections "application domains" and "common programming" illustrates clearly what is known as "academia language", i.e. advanced, mature features and lack of real application stories and libraries.

progman• 11 years ago

One point is missing: the state of debugging.

Current state: https://wiki.haskell.org/Debugging

For comparison (F# and Ocaml):

  https://msdn.microsoft.com/en-us/library/ee241127.aspx
  http://oqamldebug.forge.ocamlcore.org/

the-owlery3• 11 years ago

I've avoided Haskell, primarily because:

* hearing how difficult it is to learn, and

* recalling C++ & Java, not crazy about the idea of going back to having to specify types for everything.

But Haskell is enticing to me:

* bindings to C-libraries in general (been meaning to try GTK, and wanted to use SQLite for a small project)

* apps start-up quickly

* compiled (good performance)

What's the Haskell community like?

Is Haskell a practical language/ecosystem, or more academic-focused?

boothead4• 11 years ago

* recalling C++ & Java, not crazy about the idea of going back to having to specify types for everything.

This is a big misconception. The type system in Haskell becomes much more of a tool than a hindrance. Although you will tend to write type signatures for all your top level functions, type inference is very good and it's not necessary most of the time.

The reason you should consider writing at least the top level signatures is that when you do the compiler will help you fill in the banks with type holes. See

* https://www.reddit.com/r/haskell/comments/19aj9t/holedriven_...

* https://wiki.haskell.org/GHC/Typed_holes

Once you learn these tricks, it can really feel like magic sometimes. :-)

sklogic13• 11 years ago

recalling C++ & Java, not crazy about the idea of going back to having to specify types for everything.

In the dynamically typed languages static types are substituted with tons of trivial (stupidly trivial) tests, which is a way much more lines of code than with just simple type annotations.

digitalzombie2• 11 years ago

* hearing how difficult it is to learn, and

I thought it was pretty straight forward coming from Erlang.

The biggest thing for me was practice thinking in recursion.

srtjstjsj2• 11 years ago

The person you are replying to, unawares of the difference between static typing and type inference, is not going to find Erlang any easier to learn.

digitalzombie2• 11 years ago

* hearing how difficult it is to learn, and

I thought it was pretty straight forward coming from Erlang.

The biggest thing for me was practice thinking in recursion.

edit: Erlang and Haskell was just side hobby. I didn't do anything major with them. But I thought the languages were small enough, Haskell has such a clean looking syntax.

Oh, I think you're trying to say the threshold of being good with haskell is much higher? Cause I see that argument quite and bit.

the-owlery3• 11 years ago

> * hearing how difficult it is to learn, and
I thought it was pretty straight forward coming from Erlang.
The biggest thing for me was practice thinking in recursion.

I use Clojure, generally like functional programming, and am fine using recursion.

Haskell has such a clean looking syntax.

I have gotten fond of Clojure's Lisp-like syntax.

Oh, I think you're trying to say the threshold of being good with haskell is much higher? Cause I see that argument quite and bit.

Not sure -- haven't spent any time with Haskell. Never tried Erlang either. Do you think it generally takes longer to become productive with Haskell than with other functional programming languages?

zeckalpha3• 11 years ago

recalling C++ & Java, not crazy about the idea of going back to having to specify types for everything.

I want to reiterate the other comments and clarify: C++ & Java have poor type systems compared to Haskell. Haskell's not only is much safer, but it also allows for much much better inference, so you rarely ever need to add type annotations. People do typically add top-level annotations, for documentation's sake, in most cases, but they are not required.

airza• 11 years ago

Trying to get a Haskell application deployed to the web was an exercise in frustration. Somehow my resolution for its important package management and binaries has become profoundly fucked up as well.

dukerutledge• 11 years ago

Really? Deployment has always been a breeze for me. Build on a vm, scp the binary up to my server, profit.

State of the Haskell ecosystem

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