Why GitHub used Haskell for Semantic • Hacker News Board

Re: Why GitHub used Haskell for Semantic

#21

Post by _bxg1 » Thu, Jun 06, 2019, 1:05 AM UTC

jerf wrote: post #18

_bxg1 wrote: post #12

Earlier quoted context omitted.

To be fair I haven't really used it, only read the core of the guide, so I may be mistaken. But I've done a bit of Clojure, and I've done a bit of Immutable.js, and particularly when you have a deeply-structured piece of data, "mutating" something a few levels down gets really ugly. Now, maybe something about Haskell Enlightenment obviates this case entirely in a way I'm not seeing. But I also remember Haskell seemin…

"Now, maybe something about Haskell Enlightenment obviates this case entirely in a way I'm not seeing." Many times the answer is that with a different structure you don't need deep mutation to be a critical part of your program. After all, "deep mutation" isn't considered a great idea in object-oriented languages either, where it constitutes a violation of the Law of Demeter [1], either in letter or in spirit (i.e.,…

I hadn't seen that kind of thing; that's good to know about

Re: Why GitHub used Haskell for Semantic

#22

Post by thrower123 » Thu, Jun 06, 2019, 1:08 AM UTC

garmaine wrote: post #20

_bxg1 wrote: post #4

I'm really curious why Haskell has seen so little adoption in industry. Is it just the difficulty? Or a chicken-and-egg effect with tooling and libraries? One thing I've wondered is if it actually isn't ideal for a lot of cases. FP is beautiful for certain things. But in some domains (or pieces of domains), state and mutation aren't just unfortunate implementation details, but a core element of the problem space. For…

> The most successful languages let you be pure-functional where it makes sense and then stateful where it makes sense. Haskell doesn't, really (from my cursory reading about it). This is absolutely wrong. Sorry to be so direct, but I want to make sure other people not familiar with Haskell don’t get the wrong impression. Haskell is explicitly designed to separate purely functional and stateful code with a clear inte…

Whenever I've used Haskell, the monads infect things like a virus, similar to the way async/await metastasizes across a C# codebase.

Note: I am not very good at Haskell.

Re: Why GitHub used Haskell for Semantic

#23

Post by thrwayxyz » Thu, Jun 06, 2019, 1:10 AM UTC

tathougies wrote: post #6

_bxg1 wrote: post #4

I'm really curious why Haskell has seen so little adoption in industry. Is it just the difficulty? Or a chicken-and-egg effect with tooling and libraries? One thing I've wondered is if it actually isn't ideal for a lot of cases. FP is beautiful for certain things. But in some domains (or pieces of domains), state and mutation aren't just unfortunate implementation details, but a core element of the problem space. For…

I havr never noticed immutable data structures to be more difficult to deal with. For the most part, because of monads and effects and such you can essentially write better imperative code in haskell. Im noy sure why youve decided that haskell is incapable of the syntactic appearance of mutation.

You're lucky enough if you can find a developer who knows mutable data structures outside of SF. If you want immutable ones you need to add a zero to their wage.

Most shops aren't prepared for that.

Re: Why GitHub used Haskell for Semantic

#24

Post by _bxg1 » Thu, Jun 06, 2019, 1:10 AM UTC

dmix wrote: post #19

_bxg1 wrote: post #4

I'm really curious why Haskell has seen so little adoption in industry. Is it just the difficulty? Or a chicken-and-egg effect with tooling and libraries? One thing I've wondered is if it actually isn't ideal for a lot of cases. FP is beautiful for certain things. But in some domains (or pieces of domains), state and mutation aren't just unfortunate implementation details, but a core element of the problem space. For…

It's 100% the difficulty. Anyone saying otherwise is lying because they want Haskell to be popular, adopted it very early on in their career when they could really invest in it, or is a natural at this type of stuff and simply doesn't know any better. I've learned about 10 different languages now and Haskell easily had the highest learning curve. Most languages I was able to get semi-usable in within a couple days, a…

You seem like someone who could answer this: why use PureScript over Elm?

Re: Why GitHub used Haskell for Semantic

#25

Post by llamathrowaway » Thu, Jun 06, 2019, 1:18 AM UTC

_bxg1 wrote: post #4

I'm really curious why Haskell has seen so little adoption in industry. Is it just the difficulty? Or a chicken-and-egg effect with tooling and libraries? One thing I've wondered is if it actually isn't ideal for a lot of cases. FP is beautiful for certain things. But in some domains (or pieces of domains), state and mutation aren't just unfortunate implementation details, but a core element of the problem space. For…

> But in some domains (or pieces of domains), state and mutation aren't just unfortunate implementation details, but a core element of the problem space

True, but I would argue that it is far, far more common for people to writing stateful code to do things that are better done in functional style, than the other way around. This comes from my own experience of learning functional programming in JavaScript (before knowing about Haskell et al) and refactoring a project into a functional style that relies heavily on immutability.

I think Haskell is not more widely used in the industry because it has a very academic reputation. If you say you write Go, people think you are a practical programmer who turns coffee into solid business logic that powers some profitable website. You write Haskell? Then you are more likely to be perceived as some eccentric scholar or their like.

Re: Why GitHub used Haskell for Semantic

#26

Post by dllthomas » Thu, Jun 06, 2019, 1:18 AM UTC

jrockway wrote: post #3

> given Go's lack of exceptions, such a feature would be entirely impossible. Haskell is a nice programming language, but ultimately if a program written in language A can run on your computer, a program can be written in language B that can run on your computer and do the same things. If you think "return foo, err" is a lot different than return "Left foo" or "Right err", then you might want to think more about how…

If you think x * y is a lot different than x + y, then you might want to think more about how you think about algebraic expressions, yeah?

Re: Why GitHub used Haskell for Semantic

#27

Post by Ixiaus » Thu, Jun 06, 2019, 1:19 AM UTC

_bxg1 wrote: post #4

I'm really curious why Haskell has seen so little adoption in industry. Is it just the difficulty? Or a chicken-and-egg effect with tooling and libraries? One thing I've wondered is if it actually isn't ideal for a lot of cases. FP is beautiful for certain things. But in some domains (or pieces of domains), state and mutation aren't just unfortunate implementation details, but a core element of the problem space. For…

I actually think it's seeing quite a bit of adoption in industry. What I'm seeing is a class of developer that won't learn it or thinks they can't learn it, of course "to each their own", but I truly think Haskell/PureScript/Idris/Agda are onto something remarkable: making the software industry more like an engineering discipline and less of a craft (i.e. like the difference between civil engineering and carpentry).

Your argument RE: immutability and purity hampering implementations: Haskell excels at allowing developers to start with impure IO-heavy code, allowing you to later refactor chunks of the implementation out to pure code. In-fact, I talk about Haskell as the language you use to "move fast and _not_ break things". It also encourages a more principled approach to software design and reasoning than many other programming languages.

I've used Haskell (and seen it used) in production for many different problem domains for the last seven years of my career. I have yet to see something Haskell/GHC cannot handle well with a few niche exceptions.

In my time using Haskell I've come to think of "mutation" as a cardinal sin in software and you better have a good reason for committing it instead of letting the compiler do it for you (you can write mutable code in Haskell, too, btw - it just strongly discourages you from doing so and it makes some classes of mutable code impossible to write, which is a very, very good thing).

As a (very) fallible generalist, Haskell is a godsend and we use it extensively where I work for shell-scripts, for code generation, for (performant) network packet parsing, HTTP web servers, gRPC micro-services, and even our "build bot".

Re: Why GitHub used Haskell for Semantic

#28

Post by dmix » Thu, Jun 06, 2019, 1:23 AM UTC

_bxg1 wrote: post #24

dmix wrote: post #19

Earlier quoted context omitted.

It's 100% the difficulty. Anyone saying otherwise is lying because they want Haskell to be popular, adopted it very early on in their career when they could really invest in it, or is a natural at this type of stuff and simply doesn't know any better. I've learned about 10 different languages now and Haskell easily had the highest learning curve. Most languages I was able to get semi-usable in within a couple days, a…

You seem like someone who could answer this: why use PureScript over Elm?

Honestly I've never fully given Elm enough of a run-through to say yet (ditto with OCaml). I remember 2yrs ago I was evaluating it but decided to learn React/Vue.js for professional reasons. Additionally I wasn't convinced that Elm would be an ideal long-term commitment and more of a compromise between JS, FP, FRP (functional reactive programming) and more of a framework competitor than a full-blown language.

While I see PureScript as a full long-term language-level commitment to Haskell style FP minus the purity. But again my exposure to it has been too limited to have a strong opinion.

Re: Why GitHub used Haskell for Semantic

#29

Post by simplecomplex » Thu, Jun 06, 2019, 1:27 AM UTC

_bxg1 wrote: post #4

I'm really curious why Haskell has seen so little adoption in industry. Is it just the difficulty? Or a chicken-and-egg effect with tooling and libraries? One thing I've wondered is if it actually isn't ideal for a lot of cases. FP is beautiful for certain things. But in some domains (or pieces of domains), state and mutation aren't just unfortunate implementation details, but a core element of the problem space. For…

Very few programmers are proficient in Haskell, and operating systems and language tooling are built around imperative C-style semantics.

Combine that with the fact that most of the software industry does not care about correctness or stable software and generally lacks professionalism. "Just ship this half-assed software as soon as possible" is the attitude at the majority of software companies.

Re: Why GitHub used Haskell for Semantic

#30

Post by smackmybishop » Thu, Jun 06, 2019, 1:27 AM UTC

thrower123 wrote: post #22

garmaine wrote: post #20

Earlier quoted context omitted.

> The most successful languages let you be pure-functional where it makes sense and then stateful where it makes sense. Haskell doesn't, really (from my cursory reading about it). This is absolutely wrong. Sorry to be so direct, but I want to make sure other people not familiar with Haskell don’t get the wrong impression. Haskell is explicitly designed to separate purely functional and stateful code with a clear inte…

Whenever I've used Haskell, the monads infect things like a virus, similar to the way async/await metastasizes across a C# codebase. Note: I am not very good at Haskell.

Probably because async/await IS a monad. Avoiding that infection just takes some design experience.