Here is how my data object looks like and I tried to implement it like I am not sure if it is a good solution or we can write it in compact way. It also shows the correct number but if I try to use it in TypeScript I am a TS error ts(2769) Answer You can use R.chain with
Tag: functional-programming
Convert a list of objects with a range of minutes to an hourly list
I have a list with minute blocks objects, it contains the start and end hour/minute, according to this I must build a new list of blocks by hour and minutes occupied. Always in the same range below one hour, for this example only 30 minutes, and they cannot overlap. Example of minute block (30-minute block st…
How to apply Direct function in Stream.map() like in JavaScript
Have a question, when I use a stream map in Java I have to be explicit with the lambda. Suppose I have this mapper function: And then I want to apply it to a certain List, I have to do this: So my question is if I can do something similar to what can be done in JavaScript, like Like
Chunk array based on conditional logic using ramda
I have an array of sizes that I’d like to reduce + chunk based on custom logic using ramda: If the cumulative total exceeds the 50 threshold I would like to chunk them up, so that the result becomes: I’ve tried using reduceWhile and splitWhen but with no luck so far Answer Reduce the array to a new array. On…
Does future in c++ corresponding to promise in javascript?
I am a c++ programmer and tried to study std::future and std::promise these days. When I randomly search some information about future/promise, I found some discussion about future/promise in javascript and promise in javascript has then function. In c++, even though std::future don’t have then function…
How can you reduce(…) the entries of a JavaScript Map object without expanding to a list?
It seems there’s no good standard library way of doing something like this? Uncaught TypeError: thismap.entries(…).reduce is not a function I assume this is due to the entries() function returning an iterator? I don’t want to Array.from(thismap.entries()).reduce(…), as that would unnec…
Passing _.groupBy to _.partialRight seems to give incorrect results
Here’s a JavaScript object, and here’s a code that correctly groups the items by .id in each of the two arrays ojb.a and obj.b, the result being The lambda, however, is in fact just the partial application of _.groupBy to its second argument, which is set to ‘id’, so I thought somethin…
How to implement a division function without the operator, loop or recursion?
I need to convert this function using the functional programming paradigm but I don’t know how, I can use reducer or map creating an array but I don’t know how to implement it, i can’t use divide operator, loop or recursion; Answer The way to do it declaratively is with a recursive function&…
JavaScript how to build array from nested Object using recursion without mutation
How to make this recursion without mutation, now I am mutating ids array. I want to follow functional programming principles Answer I’d avoid creating a lot of unnecessary intermediate arrays, but to each their own. Making this “immutable” is as easy as returning a new array from the getChil…
Higher-order function with recursion in Javascript
newbie here… I’m trying to grasp the concept of functional programming in Javascript, but I got stuck. I’m trying to apply a function to another function with recursion (higher-order function). Let’s say I have an input that can be a variable or an array, for example: My basic function…