ramda.js

问题 Looking at the source for Ramda.js, specifically at the "lift" function. lift liftN Here's the given example: var madd3 = R.lift(R.curry((a, b, c) => a + b + c)); madd3([1,2,3], [1,2,3], [1]); //=> [3, 4, 5, 4, 5, 6, 5, 6, 7] So the first number of the result is easy, a , b , and c , are all the first elements of each array. The second one isn't as easy for me to understand. Are the arguments the second value of each array (2, 2, undefined) or is it the second value of the first array and the

问题 Loop may be the wrong term, but it kind of describes what I am attempting. I want to give structure to flat data, but I also need to keep track of the array it came from. Basically my rules are (per array): If level 1 exists- give it the name of the item, and a typechild array. EACH time a level 1 appears (even in the same array) it should create a new entry. Inside typechild , put the any items with level >1 If NO level 1 exists- give it the name of the item, and a typechild array. My code

问题 How would I best create this function in Ramda? function get_list (value) { return [ first_transform(value), second_transform(value) ] } get_list(12) I guess this is the inverse of the map function. 回答1: You've got a few options for this. Assuming your functions are already in a list: transforms = [first_transform, second_transform]; The first option is to use R.juxt, which does pretty much exactly what you're after by creating a new function that applies the list of given functions to the

问题 I want to create a dynamic function that can simplify work with array-transforming callbacks in order to fill and expand 2d Array. Outlining the challenge I would like to create a function like this finalFunction({ array, header, ...args }, callbackFunctionToTransformArray) Restrictions The given array is always a 2d array The header is supplied as a string to be passed onto the callbackFunction The callback function always has to return a "changes" Object containing the headers as Keys. The

问题 Need a help from Ramda community... I have an object array that I need to sort by "chapter_id" and after sorting, just remove "chapter_id": const stuff = [ { id: 1, title: "hello world", chapter_id: "4321" }, { id: 2, title: "new title", chapter_id: "21" }, { id: 3, title: "...", chapter_id: "33" }, { id: 4, title: "huh!?", chapter_id: "14" }, { id: 5, title: "From Earth", chapter_id: "11" }, { id: 6, title: "alien", chapter_id: "11" }, { id: 7, title: "Saturn", chapter_id: "11" }, { id: 8,

问题 Application of 'sortBy' producing unexpected results. I've gotta be doing something stoopid. This is such a basic operation. const input = [4,3,2,1]; const sort = list => R.sortBy(R.ascend(R.identity))(list); console.log(sort(input)); // [ 4, 3, 2, 1 ] I would expect the output of the 'console.log' invocation to be [ 1, 2, 3, 4 ], but it is not: the output is [ 4, 3, 2, 1 ], same as the input. What am I doing wrong? 回答1: As pointed out by Aadit M Shah in the comments you're not using sortBy

问题 I am a little confused in how to proceed with this scenario using ramda. Here is the JSON that I am working with. { "type" : "CartWsDTO", "Cartentries" : [ { "entryNumber" : 1, "flightGroup" : { "PAXDetails" : [ { "paxID" : "1", "paxPrice" : "770.82", "paxType" : "ADT" }, { "paxID" : "2", "paxPrice" : "770.82", "paxType" : "ADT" } ] } }, { "entryNumber" : 2, "flightGroup" : { "PAXDetails" : [ { "paxID" : "1", "paxName" : "Vinitha", "paxPrice" : "770.82", "paxSurname" : "Vinitha", "paxType" :

问题 Using functional programming in javascript and typescript together with Ramda, I often find myself writing code like: const myFun = c => { const myId = c.id const value = pipe( getAnotherOtherPropOfC, transformToArray, mapToSomething, filterSomething, // ... N other transformations // ok now I need myId and also the result of the previous function chainMyIdWithResultOfPreviousFunction(myId) )(c) return value } Notice how creating a const myId breaks point-free style. I'd like to write myFun

问题 I have an object, of which parameters contain and array of object. I receive 1 object id and I need to find its position in that whole mess. With procedural programming I got it working with: const opportunitiesById = { 1: [ { id: 1, name: 'offer 1' }, { id: 2, name: 'offer 1' } ], 2: [ { id: 3, name: 'offer 1' }, { id: 4, name: 'offer 1' } ], 3: [ { id: 5, name: 'offer 1' }, { id: 6, name: 'offer 1' } ] }; const findObjectIdByOfferId = (offerId) => { let opportunityId; let offerPosition;

问题 I want to convert a hexadecimal string like bada55 into a Uint8Array and back again. 回答1: Vanilla JS: const fromHexString = hexString => new Uint8Array(hexString.match(/.{1,2}/g).map(byte => parseInt(byte, 16))); const toHexString = bytes => bytes.reduce((str, byte) => str + byte.toString(16).padStart(2, '0'), ''); console.log(toHexString(new Uint8Array([0, 1, 2, 42, 100, 101, 102, 255]))) console.log(fromHexString('0001022a646566ff')) Note: this method always completes. If the length of the