Questions tagged [haskell]
This challenge is related to the Haskell language. Note that challenges that require the answers to be in a specific language are generally discouraged.
19 questions
1
vote
1
answer
251
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Shorten this recursive even fibonacci implementation [closed]
I have the following Haskell code to generate the the values of the Fibonacci sequence which are even as an infinite list:
...
- 103k
11
votes
2
answers
928
views
Curry tips for Haskell programmers
Curry is the Language of the Month this month and some users are starting to get into it, so let's get some tips together.
Haskell and Curry are similar in a lot of ways and a lot of tips for Haskell ...
- 103k
18
votes
1
answer
1k
views
How to golf a fork in Haskell?
I'm trying to make a pointfree function f that can act like APL's dyadic forks/Husk's §, so ...
- 457
17
votes
3
answers
782
views
Tips for restricted source in Haskell
I tested the waters on this sort of question with python, but now I get to the real question I want to ask.
restricted-source challenges are uniquely rewarding in Haskell because of Haskell's strict ...
- 103k
8
votes
2
answers
363
views
Is there a shorter way to express this haskell idiom?
Every so often I have a function of type a -> b and a function of type b -> b -> c and I would like a function of type <...
- 103k
5
votes
2
answers
1k
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Point-free madness
This challenge is about Haskell point-free style polynomial functions.
Although you don't need to know Haskell language to do this challenge, Haskellers might have an advantage here.
Point-free ...
- 2,467
3
votes
1
answer
254
views
Min-Max GHC command line error bytes to bytes of source code
GHC command line errors can be horrible, lets make them as bad as possible. To disincentivize very long programs use the following formula to calculate your "score".
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- 47
10
votes
3
answers
708
views
Interpreted arithmetic
A little known fact is that if you turn on enough language extensions (ghc) Haskell becomes a dynamically typed interpreted language! For example the following program implements addition.
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- 103k
46
votes
34
answers
16k
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Wait, what language is this?
Recently I had the pleasure of writing a Haskell program that could detect if the NegativeLiterals extension was engaged. I came up with the following:
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- 103k
18
votes
4
answers
1k
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Tuple addition in pointfree
What is the shortest way we can express the function
f(a,b)(c,d)=(a+c,b+d)
in point-free notation?
pointfree.io gives us
...
- 103k
21
votes
12
answers
4k
views
Let's make Diet Haskell
Haskell has tuples that can be written as
(a,b,c)
However this is just syntactic sugar for
(,,)a b c
In general an n tuple ...
- 103k
-6
votes
5
answers
688
views
Sort a list without builtin functions
Your task will be to write a Haskell function that takes a list of integers and returns a sorted version of the same list. You are to do this without the use of builtins.
What are builtins?
To keep ...
- 103k
62
votes
85
answers
11k
views
Sugar Free Syntax
In Haskell the list notation:
[a,b,c]
Is just syntactic sugar for:
a:b:c:[]
And the string notation:
...
- 103k
8
votes
6
answers
2k
views
Most concise way to fold tree structures
Background (F#)
Let there be trees:
type Tree<'T> = Node of 'T * Tree<'T> list
Now lets fold them nicely with a function called...
...
9
votes
5
answers
437
views
Write biSp in point-free form using as few terms as possible
The Haskell function biSp has type signature
...
- 943
3
votes
1
answer
346
views
Immutable dictionaries in Haskell [closed]
You need to implement immutable dictionaries using only functions without any other data types (custom or built-in).
The dictionary must be indexed by any data type of class Eq and contain values of ...
- 53
21
votes
3
answers
3k
views
Shortest a -> b -> (a -> b) function in Haskell
I got the following question at a test:
Write a function f with the following type a -> b -> (a -> b). ...
- 311
88
votes
58
answers
19k
views
Tips for golfing in Haskell
What general tips do you have for golfing in Haskell? I am looking for ideas that can be applied to code golf problems in general that are at least somewhat specific to Haskell. Please post only one ...
- 1,119
11
votes
2
answers
608
views
What is a good way to deal with tasks that require arrays using Haskell?
Often a task requires real arrays. Take for instance the task to implement Befunge or ><>. I tried to use the Array module for this, but it's really cumbersome, ...
- 10.2k