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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Add functionality to object, remove those functions on export
I have a form that needs validation. It is software that requires custom validation that is depending on multiple parameters.
To create validation I want to pass the object into ...
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1answer
46 views
Create a generator that returns every permutation (unique arrangement) of positive integers up to n
I watched this video from The Unqualified Engineer on YouTube and tried out the challenge. The challenge (or interview question) is to build a generator that returns all the permutations of the ...
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1answer
34 views
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1answer
59 views
childrenCount function in old and functional styles
I'm trying to transition myself from my old coding-style (if-else, for.. in) to functional programming. I've tried to update the ...
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1answer
45 views
Count the number of vowels and consonants
So I needed to write a function that takes a string and returns a javascript object with vowels and consonants properties that maps to the number of vowels and consonants in the string
...
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1answer
34 views
JavaScript-function for to convert a dash-separated string into camel case
I have to write a function which turns a string with the words separated by dashes ( - ) into a sentence using camel case notation.
I've had the following idea for an implemenation using the ...
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1answer
41 views
Concat strings from Object or Array
How would you merge these two functions into a single more generic function?
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1answer
27 views
Loading URLs via a case statement
I have the following code which loads in a URL based on the id of a user-clicked button. I'm looking to compress it down as much as possible, and make it more modular and reusable:
...
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38 views
4
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2answers
82 views
Python common file operations generalization
Functions with common and simple file operations have started to repeat in my code. Many like this one, but with subtle differences for example:
...
6
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1answer
48 views
Extendable JavaScript module that converts between camelCase, PascalCase, and underscore_case
The basic idea is that by defining the basic functions--recognize, dissect, and ...
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1answer
53 views
Stock performance app
I'm building an app that tells you a stock's percentage change in price between two dates by using Yahoo's API. Given a stock ticker and two dates, it currently outputs the percentage return to the ...
2
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2answers
51 views
Determine whether input-output pairs represent something that could be a proper math function
The input is read in line by line from stdin.
Input Format
The first line contains an integer, T, denoting the number of test
cases. The subsequent lines describe T test cases, and ...
2
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1answer
30 views
Read group of keywords from file, modify value, store new group to variable
I would like to use the following routine in my submission script for GAMESS calculations. I am not entirely sure if this is the optimum way to go.
This function would need one of the messaging ...
4
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1answer
34 views
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 ...
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1answer
48 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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0answers
38 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
25 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
53 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 ...
2
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2answers
47 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 ...
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1answer
38 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
93 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 ...
5
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2answers
94 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
117 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
118 views
4
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1answer
60 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
56 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.
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1answer
78 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:
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0answers
28 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
38 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 ...
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2answers
78 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
67 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
41 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 ...
2
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1answer
61 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
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1answer
114 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
31 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 ...
4
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2answers
67 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 ...
5
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1answer
90 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
104 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
29 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 ...
2
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1answer
58 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
85 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
55 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 ...
5
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0answers
77 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
54 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
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1answer
73 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
65 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
79 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
votes
1answer
41 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 ...
4
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4answers
135 views
Finding the max sequence finder
Problem Statement
Find the max sequence finder.
findMaxSequence([3, 2, 3, 4, 2, 2, 4]);
...
