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Becoming Productive in Haskell

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Re: Becoming Productive in Haskell

#131

Post by dragonwriter »

QuantumRoar wrote: post #103
krick wrote: post #87

Earlier quoted context omitted.

> I also wouldn't want to do everything in Haskell. Examples, please? And why?

If you have an array that fills a significant fraction of your memory (say, tens of Gigabytes), you don't have another choice but to use mutation (Haskell doesn't support that). While quite fast, it is not in the league of low level programming languages. If you need ridiculous speeds, you don't have another choice but to use C, C++ or Fortran. Python has a lot of very useful modules. If I can solve my problem with b…

> If you have an array that fills a significant fraction of your memory (say, tens of Gigabytes), you don't have another choice but to use mutation (Haskell doesn't support that).

Haskell supports mutation, although many short tutorials don't address it and even many longer tutorials don't do much with it.

Re: Becoming Productive in Haskell

#132

Post by carterschonwald »

QuantumRoar wrote: post #103
krick wrote: post #87

Earlier quoted context omitted.

> I also wouldn't want to do everything in Haskell. Examples, please? And why?

If you have an array that fills a significant fraction of your memory (say, tens of Gigabytes), you don't have another choice but to use mutation (Haskell doesn't support that). While quite fast, it is not in the league of low level programming languages. If you need ridiculous speeds, you don't have another choice but to use C, C++ or Fortran. Python has a lot of very useful modules. If I can solve my problem with b…

i write incredibly mutation heavy code in haskell on a nearly daily basis. I've even added compiler support for doing hardware prefetch to the most recent version of ghc https://downloads.haskell.org/~ghc/7.10.1/docs/html/librarie...

there are many lovely mutable data structuers in haskell http://hackage.haskell.org/package/vector-0.5/docs/Data-Vect... is one for unboxed C-struct style arrays,

http://hackage.haskell.org/package/hashtables is a super mature stable mutable hashtable library, that is used, among other places, in agda!

..... please fact check your feelings in the future :)

Re: Becoming Productive in Haskell

#133

Post by cgag »

lubomir wrote: post #27
harry8 wrote: post #9

I don't think I have ever used a haskell program written by someone else that wasn't ghc. Is that usual? Are there now a bunch of .debs for useful things other than writing haskell that are actually written in Haskell? I'm not trolling, it's just a good test of what something is useful for when it's been around a while is to ask "Well, what has it actually been used for?"

ShellCheck [0] is actually a pretty useful tool. [0] http://www.shellcheck.net/

Shellcheck is excellent, especially since syntastic will use it without any configuration.

Re: Becoming Productive in Haskell

#134

Post by autoreleasepool »

ffn wrote: post #118
QuantumRoar wrote: post #25

Scripting languages try to seduce you to just fiddle around until the output looks like something you want. While that quickly gives you some results, I think it's a huge roadblock in the mid- to longterm. Especially when programmers are only familiar with "easy" scripting languages, there are rarely insights about the general approach to the problem until the project already grew to become an abomination. While fidd…

Absolutely, Haskell has a richness of concepts to it that's entirely in a class of its own... but that being said, Haskell is to programming what sex is to life (for a woman... because men's natural enjoyment of sex throws off my following analogy). Granted there is richness and joy in finally discovering it, one needs to realize it's important that one isn't forced into it too early. Haskell demands a lot of thinkin…

> (for a woman... because men's natural enjoyment of sex throws off my following analogy)

Pro tip: If your analogy needs a disclaimer that perpetuates gender stereotypes for it to work, then its probably sexist.

Re: Becoming Productive in Haskell

#135

Post by T-R »

dllthomas wrote: post #99
david-given wrote: post #14

The author's comments on noise chime true with me: every time I give Haskell a try I end up struggling with frustrating and opaque vocabulary, sometimes completely at odds with the way other languages use them: e.g. C++ also has functors, and they're completely unrelated to Haskell functors. I really like the author's suggestion of mentally translating Functor to Mappable. Are there any other synonyms for other Haske…

As others pointed out, the way Haskell uses the term "functor" is related to the way mathematicians had been using it for at least a decade before cfront. I agree that a shared vocabulary is important, but standardizing in a way that makes the mathematical writings on the topic more accessible seems a big win. Moreover, "functor" is a bit more precise than "mappable" - a functor is a mapping that preserves structure.…

For Monad, 'join' or the kleisli arrow (>=>) might give better intuition than bind/flatMap - maybe something like "contextComposable": kleisli arrow in the Identity monad is just function composition, and for everything else, it's function composition within a context, combining contexts according to 'join'.

Re: Becoming Productive in Haskell

#136

Post by cies »

octatoan wrote: post #51
cies wrote: post #8

Great article. I do think a better "Getting started with Haskell" guide is Chris Allen's: https://github.com/bitemyapp/learnhaskell OP's article is still a great way of wetting appetite, and sharing insights; but moving on from there is better facilitated by Chris Allen's recommendations. There is also the IDE issue; FPComplete has a web-based IDE that is good for beginners, and it is possible to setup Emacs to be a…

I think you meant "whetting". :)

Thanks.. Lol! Maybe I've never read that word so far, and only heard it spoken.

Re: Becoming Productive in Haskell

#137

Post by biftek »

lallysingh wrote: post #116
imakesnowflakes wrote: post #70

Earlier quoted context omitted.

>While fiddling around is still somewhat possible in Haskell, the language itself makes it quite difficult. Haskell kind of forces you right at the beginning to pause and think "Well, what is it that I'm actually trying to do here?"... Wouldn't Scripting languages allows one to gradually build that understanding. Suppose you end up with a lot of complex code? Ditch it and build it from scratch. Usually takes around 1…

No. The debugging time, refactor/rewrite time of writing in scripting languages is substantially longer, harder work, and distinctly unpleasant compared to just thinking and using good tools to do it right in Haskell. In Haskell, I'll often have a problem and just stare at my laptop and think for an hour. Then write a dozen lines of simple, straightforward code. The code is easy to test, and the problem is marked as…

Pausing for an hour to think about and understand your problem is important in any language. Probably more important than testing honestly.

Re: Becoming Productive in Haskell

#138

Post by JadeNB »

tel wrote: post #55
1971genocide wrote: post #34

Earlier quoted context omitted.

And what makes the model of haskell any more superior to models developed in any other field like accounting, physics or chemistry ? I am sorry, haskell is just a huge roadblock to get things done in the real world. In the real world proffesional need to juggle all sorts of models. Haskell just says "Fcuk you ! its my way or the gonadway !". I need to juggle between json, matrix, html, etc. Each of them have hundreds…

I've personally found it very easy to handle "exceptions" in Haskell. Partial answers feel "bad" in Haskell because all the core functionality is clean enough to not need them, but on the other hand that makes for some of the best tools around for dealing with partiality.

> Partial answers feel "bad" in Haskell because all the core functionality is clean enough to not need them

Not to need them, sure, but not not to use them. (I swear that's the right number of 'not's.) I don't understand why something like Neil Mitchell's `Safe` isn't just the way that things are done by default.

Re: Becoming Productive in Haskell

#139

Post by x0054 »

Could you guys explain to me what Haskell would be mostly useful for. For instance, can it be used to make a web app backend or a GUI app? Or is it mostly for mathematical calculations and such. I tried to pick up Haskell once, but I guess I just couldn't get it. I mean, I got the core concepts, wrote a bunch of starter code, like prime checker and the like. But after going through several tutorial chapters, I still could not figure out how I would use Haskell in the real world.

I don't mean to criticize or anything, just mean to understand. There are so many people who are very passionate about Haskell that it makes me think that it must be worth while to learn. But I just don't get how it would be useful for things that I do most with programming: writing Web/Desktop/Mobile apps in Swift, Python, and PHP.

Also, can you recommend a good book or resource that uses real world examples to teach Haskell?

Re: Becoming Productive in Haskell

#140

Post by arbsn »

x0054 wrote: post #139

Could you guys explain to me what Haskell would be mostly useful for. For instance, can it be used to make a web app backend or a GUI app? Or is it mostly for mathematical calculations and such. I tried to pick up Haskell once, but I guess I just couldn't get it. I mean, I got the core concepts, wrote a bunch of starter code, like prime checker and the like. But after going through several tutorial chapters, I still…

What confuses you about using Haskell for writing Web/Desktop/Mobile apps? System.IO exposes all the primitive input/output functionality one would expect in Swift, Python, or PHP, and there is an abundance of higher-level libraries for networking, parsing, graphics, etc. Haskell even has a fairly usable C FFI.

Haskell is a general purpose programming language.

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