Functional programming is a paradigm which attempts to solve computational problems by the chained evaluation of functions whose output is determined by their inputs rather than the program state. In this style of programming, side effects and mutable data are deprecated.
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1answer
84 views
Binary search in functional-style Scala
Curious to know how I can improve it, especially the pattern matching part seems a bit repetitive at the moment (lots of case x if ds(x))
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2
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1answer
23 views
Folding with trees
I was trying to implement a foldTree function to generate a balanced binary tree from a list of values using foldr (Question 2 ...
2
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1answer
35 views
Initializing an array of relative coordinates of all adjacent 2D matrix cells
The program should output this:
_1 _1
_1 0
_1 1
0 _1
0 1
1 _1
1 0
1 1
Currently I have this code:
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2
votes
1answer
27 views
Python Vector implementation that acts as a class and also a collection of staticmethods
Recently I've been wondering about ways of implementing objects in code that can be represented by other primitives. An example of this is a Vector, which can be represented by a Vector\$N\$D where ...
3
votes
1answer
81 views
Is there a better way to write these two nested loops in Erlang?
Since one month, I'm learning Erlang and I like it so much.
Today, I wrote an algorithm to solve a problem.
Some time ago, I used two nested for loops in C# to ...
3
votes
1answer
50 views
Scala Tic Tac Toe Game
This is my first Scala game. I would love some feedback on my coding style, or your brief input on how you would do it.
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4
votes
2answers
93 views
Making backtracking Sudoku solver more functional
I'm implementing the backtracking solving algorithm for a Sudoku in F#. I'm wondering if I could make my code better respect the functional programming paradigm or even just making it simpler/better.
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1
vote
1answer
78 views
Finding an entry in a Hashmap
I've been playing around with functional programming for a while now and just started learning Clojure. So the problem I'm trying to solve is the following:
I have a tree-like hashmap of tasks where ...
5
votes
2answers
78 views
Beginner Project: Bunny City
I am a Java programmer, and I just recently started learning Scala for fun. I found a group of projects here, and I tried to do the graduation excercise. The problem is, my code looks a lot like java, ...
3
votes
1answer
46 views
Resize renderer on browser window size change
For a game, there is some WebGLRenderer object that wraps around canvas element. There is need to update it's size when browser window size changes. Here goes my current code written using BaconJS. ...
1
vote
1answer
75 views
Converting object oriented style code to functional in Scala
I came across Java like Scala code that I am trying to refactor to make it functional and immutable. The first obvious flaw is that it's violating thread safety by using mutable public class level ...
1
vote
1answer
53 views
4
votes
0answers
40 views
Neatly Transforming Anorm ResultSet Into Map[Parent , (Set[Child1], Set[Child2]))]
I have a table Bill containing Bills with 0...n relationships to Material and ...
3
votes
2answers
65 views
Clojure function composition: logging results of an action performed by a “pure” function
I'm wondering how I could compose this program better allow it to grow more functionality without constant refactoring.
This is my code sample for Hacker School, so I'm less married to the results ...
2
votes
1answer
46 views
Removing duplicates from list and filtering non-letter characters
I'm just starting out in Haskell and have been set an assignment for uni where I have to create a reverse index of words in a text file and find what line numbers they appear on. I also have to remove ...
4
votes
1answer
33 views
Counting items in categories
I'm an experienced programmer that also has a little experience with functional programming, although mostly theoretical (as in hobby-level reading and very minor projects).
I recently decided to ...
3
votes
2answers
58 views
Curious fractions in functional Ruby
Problem 33 in Project Euler asks:
The fraction 49/98 is a curious fraction, as an inexperienced
mathematician in attempting to simplify it may incorrectly believe
that 49/98 = 4/8, which is ...
6
votes
2answers
43 views
Refactor module for calls to internal image service
Looking for help refactoring the following code to follow a Functional Programming paradigm.
The first function builds a configuration object with default settings and optional presets, while the ...
1
vote
0answers
21 views
Which one of these both run-length decoding algorithm is the most optimal?
I'm working out on Ocaml.org 99 problems, and I solved the run-length decode one.
Here is the solution given by the site:
...
2
votes
1answer
35 views
Aggregation of a collection of object's nested array-properties
Use Case
So our lead programmer loves to follow the NIH Anti-Pattern and consequently I'm not allowed to use Underscore.js and can only use Vanilla JS... and we have to support IE8.
The goal is to ...
6
votes
1answer
162 views
BBCode to HTML converter using functional programming
I was inspired to write a BBCode to HTML converter as I'm currently learning functional programming. I wanted achieve functional cohesion. jsFiddle
I'd like feedback on:
structuring of the code. ...
2
votes
2answers
31 views
What do you think about this custom syntax? [closed]
I'm making a programming language and I've got the basis of a virtual machine working. The next step to is design the actual syntax for the language. I'd just like to know if whether the example ...
5
votes
2answers
68 views
Decomposing bitfield with Haskell: is recursion the only way to do this?
Here's a program to take a bitfield like 7 and decompose it into the flags [1,2,4].
Ignore that the algorithm for doing this doesn't use bit shifting/is stupid.
Problems: it seems like I have to have ...
6
votes
2answers
104 views
Package manager in Clojure
I wrote a package manager in clojure that does 5 things:
depend a b //creates a and b (if they don't exist) and adds dependency on a
install a //installs a and its dependencies
list //prints out ...
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0answers
44 views
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3answers
522 views
Effective use of multiple streams
I am experimenting with streams and lambdas in Java 8. This is my first serious foray using functional programming concepts; I'd like a critique on this code.
This code finds the Cartesian product of ...
11
votes
1answer
159 views
Refractoring OOP vs. Functional Programming Approach
I am writing a python script that will call mandrills export activity api for every blog on a worpress mu install except for the main site. The script is designed to be called from a cron job on a ...
6
votes
1answer
103 views
Functional, but not recursive, tree traversal
To learn tree traversal i implemented os.walk, tail-recursive and stack-based. Unfortunately Python doesn't support tail call optimization. How do i rewrite my ...
2
votes
1answer
40 views
Loop filling a set with logging
After watching Raymond Hettingers talk Transforming Code into Beautiful, Idiomatic Python I got back to a function I wrote.
I'm not quite sure how to make it more pythonic but I think this might be a ...
6
votes
1answer
67 views
Monadic Immutable Linked List in the Least Functional Language Evar
I've written a List monad as an example for a related question. This is a rather frustrating experience as I wanted to use Java, which (as of Java 7) still lacks lambda expressions and lacks ...
4
votes
0answers
70 views
Review of genetic algorithm code in Erlang
I've written an Erlang implementation of the genetic algorithm for a hello world program described here: http://www.puremango.co.uk/2010/12/genetic-algorithm-for-hello-world/
This is my first time ...
5
votes
1answer
49 views
Conversion from decimal to negabinary and vice versa in Haskell
Recently I set about to writing conversion functions in Haskell between decimal and negabinary. I tried to write them in as much functional a style as possible, also aiming at brevity. Below I present ...
3
votes
3answers
158 views
Better way to write this code in functional manner using map and reduce?
I have an array of items on which I have to perform 2 tasks:
Applying a function on the array item
Checking if the value is true or false.
The functional approach to solving this would be
...
4
votes
1answer
55 views
Good OCaml style
I wanted to write a small but non-trivial function in OCaml to test my understanding. I have only a basic understanding of the libraries, and no idea at all of what is considered good style. The ...
5
votes
1answer
108 views
Read text from stream char by char
I've started learning F# and functional programming in general, but the code I wrote doesn't seems to be really functional. Could you take a look and say how to make it more as it should be in ...
6
votes
4answers
260 views
Functional approach to splitting list into sub lists
Here is my functional approach to split a list into sub lists, each having non-decreasing numbers, so the input
\$[1; 2; 3; 2; 4; 1; 5;]\$
computes to
\$[[1; 2; 3]; [2; 4]; [1; 5]]\$
The code ...
2
votes
1answer
83 views
Filtering a dictionary by subject of definitions
I am writing a function to filter a "dictionary" by the "subject" of its definitions.
The dictionary data structure is a hash-map of this kind:
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10
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1answer
126 views
(How) should I avoid writing procedural code in Haskell?
I'm trying to implement a left leaning red black tree as described here. This is their snippet for insert
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6
votes
1answer
220 views
Reading input from the console in F#
In the process of learning F#, I wrote this code that reads lines of input from the console and stores them in a list.
As far as I can tell the code works correctly, but since I'm new to functional ...
3
votes
0answers
85 views
Elixir pipes and anonymous functions
I recently got started with Elixir. I'm used to F#'s pipes, and Seq.map and LINQ's .Select statements. Things are different in ...
2
votes
1answer
80 views
Functional Re-Write in Scala: Rows of Strings with a Max Width
I came across an issue the other day where I really just could not think of a functional solution. So I fell back on my imperative programming skills. Since a functional solution still eludes me, I ...
4
votes
1answer
90 views
Centroid of a polygon in Clojure
I am studying Clojure and functional programming. I wrote this function to compute the centroid of a polygon specified as a vector of points, e.g. ...
5
votes
1answer
297 views
Code with many “early returns (exits)” into the functional style
I have some Scala code that uses Internet to authorize a user. Therefore, it can throw Exceptions like IOException in the method.
The original code was written in ...
7
votes
1answer
748 views
Clojure Neural Network
After reading this article about Neural Networks I was inspired to write my own implementation that allows for more than one hidden layer.
I am interested in how to make this code more idiomatic - ...
2
votes
2answers
165 views
“Hell Difficulty” Haskell Fast & Hard
I'm a complete neophyte to Haskell with only a smidge of FP experience – I did some Racket programming academically and have written some semi-FP JavaScript professionally, but now I'm trying to learn ...
1
vote
0answers
134 views
Review my F# Red Black Tree Implementation [closed]
I have written this implementation for red black tree. I also have some helper methods to verify whether the generated tree is really balanced or not.
Looks good to me.... but I find that most of the ...
3
votes
1answer
78 views
Hangman game background image inefficient?
I'm making a Hangman game and it seems that my code doesn't provide me much freedom with using layouts. I added an image to my JFrame then I added a JPanel to my image which I'm using for all the ...
1
vote
1answer
136 views
Review my F# QuickSort Program
OK... last sort of the day and probably the most fun. F# is really awesome.
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1
vote
1answer
121 views
Merge Sort Program
I have written the following program to implement merge sort in F#.
Can you please review this and let me know how can I write this in the most functional way (also most efficient and concise)?
In ...
1
vote
2answers
61 views
Review my F# BubbleSort Program
I have written this code for BubbleSort in F#. Can you review and let me know how I can do this in most functional way.
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