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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Checking if input file exists, assign output file destination, prevent overwriting any files
I would like to use the following routines in my submission script for GAMESS calculations. Before I do, I would like to get some input if I can improve it somehow.
The three messaging routines ...
3
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0answers
16 views
Function to read in valid line (string) in C
I'm very familiar with the pitfalls associated with reading in a line (string) in C++ and Java. Hell, library functions in these languages handle most of the issues anyhow. But in C, I've found it ...
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1answer
34 views
Gulp task to increment a major, minor, or patch level of the version number of the last build
Working codepen: http://codepen.io/leongaban/pen/oxwLzE?editors=1010
The function below takes in user entered text through the cli: V=patch gulp build
It then ...
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15 views
Merging trees in scalaz
I just built a function to merge a set of List[A]s into a single scalaz.Tree[A].
Specifically, if I have the following three ...
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1answer
21 views
JavaScript function for logging the members of an object (with horizontal alignment)
When iterating over the members of an object for logging the keys / values one gets a "stair case" effect.
Therefore I wrote myself this function which takes care for a left-alignment of the values.
...
3
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1answer
44 views
Clojure reverse multiple times
I have a piece of Clojure code that reverses a string recursively.
It is working but too slow (because I got the problem from Codewars and I cannot validate it ...
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2answers
43 views
PE # 34 - “Digit Factorials” with no loops
I posted a similar question “Curious Numbers” (HackerRank PE 34) recently (but in a different language/platform altogether). I'm starting to learn JavaScript and decided to take the challenge again ...
3
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1answer
29 views
Find zeroes in a matrix
I am looking for the elements that are zeroes in a square matrix (of size n), as a list of pair. I don't really like the following code, some condition seems ...
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1answer
67 views
“Curious Numbers” (HackerRank PE 34)
I was inspired by a certain recent question to try my hand at this challenge:
Project Euler #34: Digit factorials
\$19!\$ is a curious number, as \$1!+9!=1+362880=362881\$ is divisible
by ...
4
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56 views
Recursion task - optimization
I need your review and suggestions how to make this code better. I'm just learning recursion and sure that this solution is not ideal.
Question:
Write a function that given an input array of ...
5
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2answers
88 views
Document term matrix in Clojure
This is my very first foray into Clojure (I'm normally a Python-pushing data-type). I'm trying to create a simple term-document matrix as a vector of vectors, out of a vector of strings.
For those ...
4
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2answers
112 views
A curry function
I am new to the functional style, and I wrote a curry function to practice this new style. This curry function takes a regular function and returns the curried version of it. Currying is a technique, ...
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2answers
106 views
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1answer
59 views
C++ idiom for selecting integers from a vector according to predetermined properties
I want a function Select that takes a vector<int> and a condition (such as being even, being divisible by three, being ...
6
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1answer
53 views
All possible ways of merging two lists while keeping their order
I am writing a function gives all possible ways of merging two ordered lists such that in the merged list, the elements are still ordered according to the elements in their respective starting list.
...
2
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1answer
71 views
Recursive function application
I use a lot T4 templates and want to avoid extra code writing when it could be generated. Currently I have following class:
...
2
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0answers
24 views
Reformatting a structured string like “a-b-c|A-B-C” into “a-A|b-B|c-C”
The code below was inspired by this post in Code Review.
Here is how it was first intended by its author:
I have the following code that converts a string that looks like :
...
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0answers
29 views
Extracting data for a tag cloud using Lazy.js
I've just started using Lazy.js, which is my first exposure to a "functional style" javascript library. I'm still utterly lost as to which of the hundred different functional javascript libraries to ...
8
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2answers
71 views
Compiler for a minimal LISP dialect to run on the Java Virtual Machine
As the title states, this is a compiler written in C with a ruby build script that translates a minimal LISP dialect and spits out an executable jar file. I designed this LISP dialect and named it ...
3
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1answer
59 views
Quick-sort a linked list?
I have a little project where i am implementing an immutable linked-list (not only...) based on a pair-structure like the LISP cons-cell.
The linked list works well and is basically wrapping two ...
3
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0answers
34 views
Refactored version of Okasaki's skew-binomial heaps in Standard ML
In his book, Purely Functional Data Structures, Chris Okasaki provides an implementation of skew-binomial heaps (p. 137). Unfortunately, the book isn't (legally) freely available anywhere, but his ...
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1answer
48 views
Functional Scrabble Word Score
Homework: Write a function to score a scrabble word.
values is a global dict formatted as values = {'a': 1, 'b': 3,...}
The ...
3
votes
1answer
86 views
Object-oriented web scraping with Python
I usually write function-only Python programs, but have decided on an OOP approach (my first thereof) for my current program, a web-scraper. Here is the working code I wrote which I am looking to have ...
0
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1answer
30 views
ES6 block-scope variable usage
I am experimenting with ES6 using BabelJS in a codepen project you can find here. I am confused as to why my code breaks when I decide to use let instead of ...
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2answers
64 views
Functional translation of dice simulation
I have tried my hands at "functionalising" a toy problem I had: find the expected number of throws of a six sided die until all sides have been seen (the answer is 14.7)
My starting point is my ...
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1answer
89 views
Option<T> functional type implementation and scenarios
Have you ever being implementing Option<T> functional type? It is discussed here. Basically, it is about using ...
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1answer
57 views
Functional Javascript Practice with AJAX
I am currently doing projects in freecodecamp.com to brush up on my javascript skills and just finished a weather report widget. It does the following:
Gets api ...
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0answers
25 views
PBKDF2 and HMAC implementation in Scala
First of all: I know that rolling your own cryptographic functions is bad. The SHA256 implementation i use is from Bouncycastle, but i think both HMAC and PBKDF2 are not vulnerable to timing attacks ...
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1answer
26 views
Implementing an inner product using pyspark
I'm trying to implement a dot product using pyspark in order to learn pyspark's syntax.
I've currently implemented the dot product like so:
...
2
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1answer
83 views
Grouping an array by postId and userId
I've got this kind of data:
[
{ userId: 1, postId: 1, ... },
{ userId: 1, postId: 2, ... },
{ userId: 2, postId: 3, ... },
...
]
And I need to group them ...
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2answers
53 views
High order functions on Array.prototype
In order to better understand functional programming in Javascript, I thought I'd try to recreate (as well as extend) some of the higher order functions on the Array object. These methods don't intend ...
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0answers
62 views
In-lining InvocationExpressions
This is regards to one of my answers: Linq Expression Calling Combines. The question wasn't very well received, but it proved to be an interesting task that I enjoyed working on.
I ended up with the ...
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2answers
49 views
Adding polynomials represented as maps
I'm using maps to represent a polynomial.
The key is the exponent and the value is the coefficient : Map(exp -> coef)
e.g. ...
5
votes
1answer
70 views
Project Euler problem 11, finding adjacent numbers with the greatest sum
The full description of the problem to solve can be found here. The code I have written works fine but seems extremely verbose for what it's doing, I'm not sure if list comprehensions are meant to be ...
4
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2answers
63 views
FizzBuzz functional implementation
I was playing around with ES6 arrow functions, currying and partial application and I decided to try a functional implementation of the FizzBuzz problem:
...
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2answers
66 views
Write an anonymous function validating email address
Problem statement
Write an anonymous function which take email address as parameter and returns true/false after validating the input parameter.
Objective
This assignment will help ...
5
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1answer
38 views
Binary to ascii mapping in JavaScript
This morning I've seen this on Twitter:
http://mynewtechworld.tumblr.com/post/135545896048
I case that somebody can't see the image:
I
01101100
01101111
01110110
01100101
you.
Just ...
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4answers
97 views
Finding the max sequence finder
Problem Statement
Find the max sequence finder.
findMaxSequence([3, 2, 3, 4, 2, 2, 4]);
...
3
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2answers
24 views
OOP, FP and IMP condensed in Rock, Paper and Scissors
Rock Paper and Scissors is a pretty basic program.
The reason I wrote this program is because I wanted to see what a small script that used all of the main programming paradigms looked like.
My code ...
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4answers
712 views
Project Euler 6: Difference between sum of squares and square of sum
I've created a (very) simple solution for Project Euler problem 6:
Project Euler Problem 6: Sum square difference
The sum of the squares of the first ten natural numbers is,
$$ 1^2 + 2^2 ...
5
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1answer
224 views
Project Euler Problems #1-#5
Since I've been playing with F#, I decided to try my hand at implementing some of the Project Euler problems, and I've been having a blast doing it. (f#-is-fun)
So, I'm going to list all the Project ...
3
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1answer
142 views
RxJS Subscription Service in Webworker
Here is a plunker of my working demo.
I have the following code which I have created for a subscription service for data through a webworker. I was wondering if I was following functional-reactive ...
21
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6answers
3k views
To 'this' or not to 'this'?
I was given a homework and I have 2 solutions: one that uses this and other one that doesn't.
I tested it on jsPerf but sometimes it says the version with ...
2
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2answers
72 views
Reduce array of objects into object of arrays
I have an array of objects where each object has two keys: key (k) and value (v). I need to make an object that would take ...
10
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1answer
63 views
Printing patterns in Haskell
Write a function Int -> Char -> Char -> [String] that will create the appropriate pattern.
For example: ...
4
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4answers
247 views
Mastermind: Evaluating the guess
The evaluate_guess function below returns the evaluation of a guess with respect to Mastermind game rules:
...
6
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1answer
92 views
Game of Life rules in 14 lines of Python
I've attempted a functional solution to Conway's Game of Life in Python.
The example code allows you to see the next generation of the universe by calling the ...
6
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1answer
65 views
Improving multiple assignment using an iterator function
Often I need to perform multiple assignment from a sequence
(e.g. from the result of a split()) but with some semantics
that, AFAIK, are not available in the ...
1
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1answer
60 views
Currying addition function in ECMAScript 6
I wanted to write an add function that implemented currying in JavaScript. I welcome criticism and suggestions for improvement.
...
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1answer
202 views
Ordered dictionary in swift 2
Loosely basing myself on this blog post, I implemented an ordered dictionary. In essence, it's a wrapper struct for a list of tuples with some initialisers and some functions (map, filter, toArray, ...
