Questions tagged [functional-programming]
The principles of functional programming revolve around constructing abstractions with functions, separating side effects and mutable state. Running pure functions ensures thread safety.
Imagine the scenario: def x_squared(x): result = x * x return result def twice_x(x): result = 2 * x return result def x_cubed(x): result = x * x * x return result x_values = np.array([1, 2, 3]) functions = np.array([x_squared, t ...
Looking to generate a list of natural numbers between 1 and 1000 that are multiples of either 3 or 5. I attempted using a list comprehension: [x for x in range(1, 1000) if x % 3 == 0 or x % 5 ==0] This raises the question: Is there an elegant method fo ...
Can someone help me create a function in JS or TS that meets the following requirements? I am looking for a functional programming approach. ・Input type: Array(String) ・Output type: string or undefined Examples Input Result ["" ...
Recently, I began working with fp-ts and wanted to create a method with functional-like behavior that would: Parse a bearer token Verify the validity of the user using the parsed token import { Request } from 'express'; import { either } from 'fp-ts'; im ...
I am currently developing a lambda function that calls another function with specific parameters. While this code runs without issues in Firefox, it encounters an error in Chrome, displaying a strange message in the inspector: Uncaught TypeError: Illegal ...
Currently, I have integrated Bacon.js into my server-side application using Express.JS (version 4.x). However, I am encountering an issue where the method does not respond at all. Can anyone help me figure out what might be causing this problem? var User ...
When dealing with a structure where each property is of type These<E, A> where E and A are unique for each property. declare const someStruct: { a1: TH.These<E1, A1>; a2: TH.These<E2, A2>; a3: TH.These<E3, A3>; } I inte ...
As I dive into learning about functions in Javascript, one thing that's causing confusion for me is the difference between function declaration and function expression. For example, if we take a look at this code snippet: function callFunction(fn) { fn ...
Exploring the strategy behind determining when to create a new component in a web application using angularjs / angular has been on my mind lately. It seems like this concept could apply to all component-based front end frameworks as well. I understand th ...
Currently, I am utilizing d3-force for collision detection in my project: function customLayout(nodesWithCoordinates) { const simulation = forceSimulation(nodesWithCoordinates) .force('collide', forceCollide(4.5)) .stop() .tick(300 ...
I'd prefer to sidestep the challenge of nesting numerous providers around my app component, leading to a hierarchy of provider components that resembles a sideways mountain. I aim to utilize composition for combining those providers. Typically, my pro ...
I have a specific object structure that contains information about countries and their respective cities: const geo = { europe: { germany: ['berlin', 'hamburg', 'cologne'], france: ['toulouse', ' ...
I have a Typescript cat class: class Kitty { constructor( public name: string, public age: number, public color: string ) {} } const mittens = new Kitty('Mittens', 5, 'gray') Now I want to create a clone of the inst ...
Considering implementing logging within a composed chain of functions, the following code demonstrates how it can be achieved: const f = R.compose( transformation2, doAlso(x => console.log(`id: ${x.id}`)), transformation1 ) This approach would c ...
Currently, I am working on a node.js application that includes a registration function. Within this function, the challenge lies in verifying whether a username has already been taken or not. My issue arises from the fact that the SQL module in node only a ...
I'm currently working on optimizing a function that retrieves JSON data stored in localStorage using dot notation. The get() function provided below is functional, but it feels verbose and limited in its current state. I believe there's room for ...
Is there a better way to phrase this question? Please feel free to correct me. If I wanted to create a histogram using functional programming in Python without any external libraries, how would it be done? def add_value(bins, x): i = int(x // 10) ...
I have implemented a promise function in the following way: // WORK let res = {approveList: [], rejectList: [], errorId: rv.errorId, errorDesc: rv.errorDesc}; for (let i = 0; i < rv.copyDetailList.length; i ++) { const item = rv.copyDetailList[i]; ...
I've been struggling with defining a new function, and I need help resolving it. Here's an example that I was initially referencing: Pass arguments into ajax onreadystatechange callback? I wasn't able to find the solution through research, ...
I am currently working with a data structure that is structured similarly to the following: var data = { "id": 123, "modules": [{ "id": 1, "results": [{ "status": "fail", "issues": [ {"type": "ch ...
What is the most common way to write a filter with negation? For example: is_even = lambda x : x % 2 == 0 odd_numbers = filter(lambda x: not is_even(x), range(10)) Of course, you could always use list comprehensions - but then there would be no need for ...
Lately, I have been experimenting with some code in an attempt to delve deeper into functional programming. However, I seem to have hit a snag. I am struggling with handling an object. My goal is to add key-value pairs to an object without reassigning it, ...
I've delved into the world of functional programming and I'm working on developing a package that needs to be configurable. My goal is to set up this configuration only once to maintain purity in my functions without relying on global state. Currently, I'v ...
We have a simple, mathematically curried function for subtracting numbers: function sub(x) { return function (y) { return x - y; }; }; sub(3)(2); // 1 The function signature matches the obtained result. However, when function composition comes i ...
I am currently utilizing React JS in an application structured like the following diagram: This particular application fetches data from a Rest API (Node express) using Axios. The challenge I am facing is determining the most effective method for storing ...
I'm looking to apply a :hover style to an element using Elm's HTML library. I've considered using Signals and Sets to manage selected nodes, but it feels like overkill for such a simple task. Another option is adding an external stylesheet, ...