7 ms·

Another article that I am too stupid to understand... how do you get anything done in Haskell...

the_af 6y ago
How do you get anything done in Haskell, you ask? Here are some steps: 1. Read a Haskell book and/or tutorials online, some of which are free. 2. Try writing simple software and reading other people's code. Ask for help when you get stuck. The Haskell community tends to be friendly and helpful. 3. Write your own non-toy code, hit real world problems and solve them. The path is very similar to other languages, except that because Haskell doesn't share the same lineage than C/C++/Java/Javascript, you won't be able to "wing it" by skipping the steps above. That's likely the source of your confusion: you can't as easily draw analogies to the languages you're already familiar with. Note that learning Haskell from exploratory articles which are meant for an audience already familiar with the language is not the best way to go about it. This is like trying to learn Java from an article describing the subtleties of the garbage collector in some interesting corner cases: it'll just confuse you and it won't have any practical lessons for the novice. People can and do write actual production Haskell code, so it can't be that hard.
- ljm 6y ago
  Worth noting that some articles may also feel inaccessible because so many examples are written in terms of formulae. There's plenty of Haskell out there that is easier to pick up on without looking at what seems to be a jumble of letters that imparts deep meaning. frobnicateM :: M a b => b -> a -> f (b a) a You might get to that stage at some point but books like writing a scheme in 48 hours will show you a much more accessible and elegant side.
  - chowells 6y ago
    That jumble of letters does impart deep meaning. In this case it tells me very precisely that you banged on your keyboard at random, because that's got an infinite kind error in it. Documentation is powerful stuff, especially when it's machine-checked the way Haskell type signatures are.
andrepd 6y ago
I don't get these kinds of comments. Have you spent any time learning any of this? If not, then why do you say that "this is very complicated and I'm too stupid"? If you find a text in German and you don't understand a word, because you have never studied German, do you think you are too stupid to speak German?
- the_af 6y ago
  I think the mistake is the assumption that there must be a quick and easy analogy to a language with C-style syntax (I'm simplifying a bit, but you get the idea). This is sort of like PG's Blub paradox: the reader opens an article, sees a bunch of seemingly bizarre syntax and novel terminology, can't easily map it to something he/she knows from C/Java/Python/Javascript, and panics. For some reason people don't assume the same about natural languages. No Western reader will take a peek at a webpage written in Japanese and cry "I can't understand how people speak this language". (Not in this day and age, at least).
  - dreamcompiler 6y ago
    And Haskell syntax is much easier to learn than Japanese syntax. (And Japanese syntax is itself easier than you might think.)
  - mumblemumble 6y ago
    I'm guessing it's because most people spend very nearly their entire careers nestled comfortably within a single programming language family. So one maybe gets used to the idea that one should be able to decipher an unfamiliar programming language just by reading it carefully, without needing to do any background study first. It's most pronounced with lisp and ml-style languages, but I've also seen Java lifers bounce off of things as innocuous as Python's list comprehensions.
    - FartyMcFarter 6y ago
      Prolog can also be pretty mind-bending at first, for people used to imperative programming.
Hitton 6y ago
Nah, that's just author over complicating simple thing (quite common among Haskell programmers). If he thought for a moment before starting Haskell, he would find out that associativity is enough for map reduce operation.
- smlckz 6y ago
  Different people learn differently. Something that is obvious to you might not be obvious to someone else. The author learnt in that way and shared that, which is a good thing. Sometimes, Haskell seems to be more mathematics than programming.
- mopierotti 6y ago
  However some map-reduce implementations implicitly expect reducers to be commutative, which the author became appropriately suspicious of because of the "typical examples" of map-reduce. I found this interesting paper on the subject of non-commutative reducers: "Nondeterminism in MapReduce Considered Harmful?" https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/icsecomp14seip-seipid15-p.pdf https://www.microsoft.com/en-us/research/wp-content/uploads/...
an_ko 6y ago
Don't be too hard on yourself. It's not stupidity but unfamiliarity. Haskell's roots are pretty distinct from most other popular programming languages, so it's normal if your existing notions from unrelated programming languages don't translate. Like if the article were written in Finnish.
- k__ 6y ago
  Why is Haskell like this? I don't have that feeling when using other FP languages like Lisp or OCaml.
  - josephg 6y ago
    Haskell programmers have delved the deepest and furthest in the mines of a certain kind of Truth. Decades under the earth gives them strange language and strange ideas - the monoid, applicators, all sorts of things. You can follow them to their deep dark places - but they have travelled far, and finding them in their tunnels is a journey of many moons. To the Haskell programmer, us surface dwellers are all confused - missing the essential True Names of programming. Don’t despair - you can travel where you will; but know that discovering the hidden truths will humble and age the best of us. Why? I know not. Perhaps realising we’re small and stupid is the cost of staring into the abyss of Math.
    - MaxBarraclough 6y ago
      The acolytes of laziness dug too eagerly and too deep.
  - the_af 6y ago
    A lot of people complain about all the parens in Lisp. I don't agree with that complaint either. Different people find different things confusing.
  - freeone3000 6y ago
    Read $ as <| and . as an empty space and it parses fine as F#. This article relies more on the underlying algebraic set theory than anything in particular about Haskell (sans the conclusion, which is an implementation detail - stick to your commutative monoids in f#'s PSeq.reduce please!).
SloopJon 6y ago
The takeaway for me, which agrees with my experience, is that QuickCheck is a great way to start testing. It's pretty amazing what you can find just by checking a few properties or invariants with a hundred random inputs each. It's kind of the seven-minute-a-day workout of testing.
rowanG077 6y ago
This comment makes me really sad. It's not that you are stupid. It's just that this article is littered with terminology unfamiliair to you(I assume).
mjaniczek 6y ago
You don't need to use the advanced features of Haskell to be productive with Haskell. On my latest project I'm writing Haskell in a largely Elm style, and it's glorious.
rkangel 6y ago
While I do agree with you about Haskell's close association with maths (and an assumption about the users), in this case the author is pursuing a mathematical proof (or rather, a counterexample to a mathematical hypothesis). The use of Haskell here is just as a tool to that end. It is therefore reasonable to expect a greater than normal amount of mathematical notation.

How do you get anything done in Haskell, you ask? Here are some steps: 1. Read a Haskell book and/or tutorials online, some of which are free. 2. Try writing simple software and reading other people's code. Ask for help when you get stuck. The Haskell community tends to be friendly and helpful. 3. Write your own non-toy code, hit real world problems and solve them. The path is very similar to other languages, except that because Haskell doesn't share the same lineage than C/C++/Java/Javascript, you won't be able to "wing it" by skipping the steps above. That's likely the source of your confusion: you can't as easily draw analogies to the languages you're already familiar with. Note that learning Haskell from exploratory articles which are meant for an audience already familiar with the language is not the best way to go about it. This is like trying to learn Java from an article describing the subtleties of the garbage collector in some interesting corner cases: it'll just confuse you and it won't have any practical lessons for the novice. People can and do write actual production Haskell code, so it can't be that hard.

ljm 6y ago
Worth noting that some articles may also feel inaccessible because so many examples are written in terms of formulae. There's plenty of Haskell out there that is easier to pick up on without looking at what seems to be a jumble of letters that imparts deep meaning. frobnicateM :: M a b => b -> a -> f (b a) a You might get to that stage at some point but books like writing a scheme in 48 hours will show you a much more accessible and elegant side.
- chowells 6y ago
  That jumble of letters does impart deep meaning. In this case it tells me very precisely that you banged on your keyboard at random, because that's got an infinite kind error in it. Documentation is powerful stuff, especially when it's machine-checked the way Haskell type signatures are.

andrepd 6y ago

I don't get these kinds of comments. Have you spent any time learning any of this? If not, then why do you say that "this is very complicated and I'm too stupid"? If you find a text in German and you don't understand a word, because you have never studied German, do you think you are too stupid to speak German?

the_af 6y ago
I think the mistake is the assumption that there must be a quick and easy analogy to a language with C-style syntax (I'm simplifying a bit, but you get the idea). This is sort of like PG's Blub paradox: the reader opens an article, sees a bunch of seemingly bizarre syntax and novel terminology, can't easily map it to something he/she knows from C/Java/Python/Javascript, and panics. For some reason people don't assume the same about natural languages. No Western reader will take a peek at a webpage written in Japanese and cry "I can't understand how people speak this language". (Not in this day and age, at least).
- dreamcompiler 6y ago
  And Haskell syntax is much easier to learn than Japanese syntax. (And Japanese syntax is itself easier than you might think.)
- mumblemumble 6y ago
  I'm guessing it's because most people spend very nearly their entire careers nestled comfortably within a single programming language family. So one maybe gets used to the idea that one should be able to decipher an unfamiliar programming language just by reading it carefully, without needing to do any background study first. It's most pronounced with lisp and ml-style languages, but I've also seen Java lifers bounce off of things as innocuous as Python's list comprehensions.
  - FartyMcFarter 6y ago
    Prolog can also be pretty mind-bending at first, for people used to imperative programming.

Hitton 6y ago

Nah, that's just author over complicating simple thing (quite common among Haskell programmers). If he thought for a moment before starting Haskell, he would find out that associativity is enough for map reduce operation.

smlckz 6y ago
Different people learn differently. Something that is obvious to you might not be obvious to someone else. The author learnt in that way and shared that, which is a good thing. Sometimes, Haskell seems to be more mathematics than programming.
mopierotti 6y ago
However some map-reduce implementations implicitly expect reducers to be commutative, which the author became appropriately suspicious of because of the "typical examples" of map-reduce. I found this interesting paper on the subject of non-commutative reducers: "Nondeterminism in MapReduce Considered Harmful?" https://www.microsoft.com/en-us/research/wp-content/uploads/2016/02/icsecomp14seip-seipid15-p.pdf https://www.microsoft.com/en-us/research/wp-content/uploads/...

an_ko 6y ago

Don't be too hard on yourself. It's not stupidity but unfamiliarity. Haskell's roots are pretty distinct from most other popular programming languages, so it's normal if your existing notions from unrelated programming languages don't translate. Like if the article were written in Finnish.

k__ 6y ago
Why is Haskell like this? I don't have that feeling when using other FP languages like Lisp or OCaml.
- josephg 6y ago
  Haskell programmers have delved the deepest and furthest in the mines of a certain kind of Truth. Decades under the earth gives them strange language and strange ideas - the monoid, applicators, all sorts of things. You can follow them to their deep dark places - but they have travelled far, and finding them in their tunnels is a journey of many moons. To the Haskell programmer, us surface dwellers are all confused - missing the essential True Names of programming. Don’t despair - you can travel where you will; but know that discovering the hidden truths will humble and age the best of us. Why? I know not. Perhaps realising we’re small and stupid is the cost of staring into the abyss of Math.
  - MaxBarraclough 6y ago
    The acolytes of laziness dug too eagerly and too deep.
- the_af 6y ago
  A lot of people complain about all the parens in Lisp. I don't agree with that complaint either. Different people find different things confusing.
- freeone3000 6y ago
  Read $ as <| and . as an empty space and it parses fine as F#. This article relies more on the underlying algebraic set theory than anything in particular about Haskell (sans the conclusion, which is an implementation detail - stick to your commutative monoids in f#'s PSeq.reduce please!).

SloopJon 6y ago

The takeaway for me, which agrees with my experience, is that QuickCheck is a great way to start testing. It's pretty amazing what you can find just by checking a few properties or invariants with a hundred random inputs each. It's kind of the seven-minute-a-day workout of testing.

rowanG077 6y ago

This comment makes me really sad. It's not that you are stupid. It's just that this article is littered with terminology unfamiliair to you(I assume).

mjaniczek 6y ago

You don't need to use the advanced features of Haskell to be productive with Haskell. On my latest project I'm writing Haskell in a largely Elm style, and it's glorious.

rkangel 6y ago

While I do agree with you about Haskell's close association with maths (and an assumption about the users), in this case the author is pursuing a mathematical proof (or rather, a counterexample to a mathematical hypothesis). The use of Haskell here is just as a tool to that end. It is therefore reasonable to expect a greater than normal amount of mathematical notation.