Counting up and down in recursive manner in JS

I am currenty working on functional programming techniques. There are topics about this issue [ especially there is one about java ] but not about JS. I want to create a recursive function that can …

How can I combine multiple reducers in Ramda?

I’m trying to build reports by combining several different functions. I’ve been able to get what I want using some vanilla javascript but it’s way too wonky and I know I’d be better off if I can use …

How to return an Immutable object from a factory function in JavaScript

I have a basic function accepts Temperature data as an argument and then perform a simple temperature conversion operation on the data How can we perform the same functionality using without mutating …

ramda transducers with final R.sum

I’m trying to understand Ramda’s transducers. Here’s a slightly modified example from the docs: const numbers = [1, 2, 3, 4]; const isOdd = (x) => x % 2 === 1; const firstFiveOddTransducer = R….

What is the flow of execution with this compose function passed into Javascripts reduce?

I just want to know how reduce works in the case of code below(which was provided by a stackoverflow user in my previous question, i’m asking this question as his code snippet led to me having more …

Javascript – Using compose with reduce

I am learning functional programming with javascript. I have learned that 2 parameters are needed for reduce. Accumalator and the actual value and if we don’t supply the initial value, the first …

Ramda: How to remove keys in objects with empty values?

I have this object: let obj = { matrimonyUrl: ‘christian-grooms’, search_criteria: ‘a:2:{s:6:”gender”;s:4:”Male”;s:9:”community”;s:9:”Christian”;}’, mothertongue: null, religion: ‘…

Lodash reject point free

Is it possible to avoid point in this example? _.reject([1, 4, null, undefined, 2, 5], item => _.isNull(item) || _.isUndefined(item)); // -> [1, 4, 2, 5]

reduce function composed of map function in JavaScript

Say we have and want to reduce() it like Now, I want to compose reduce() function itself from map() function. How would you do that? What is the smartest way? Edit: In the comments and answers, many have claimed fold/reduce can compose map, in shallow level, that can be true, however, in category theory, fundamentally reduce/fold is generalized to Catamorphism and it’s all about functors (map), and it’s called F-algebra. https://en.wikipedia.org/wiki/Catamorphism https://en.wikipedia.org/wiki/F-algebra Answer If you’re trying to build the map function using reduce, you could do the following (The example I’m providing will use built-in functions and work for arrays

Get first element of a collection that matches iterator function

I would like to achieve something like _.first with _.filter, that is, having a collection of elements, I’d like to get the first one (if exists) that matches a truth test (iterator). For example, …