In this lesson we'll learn the basics of using lenses in Ramda and see how they enable you to focus changes on specific properties of an object while keeping your data immutable. what 'R.lens' do is able to get or set prop value but keep the object i…

Sometimes you need to filter an array of objects or perform other conditional logic based on a combination of factors. Ramda's where function gives you a concise way to declaratively map individual predicates to object properties, that when combined,…

We don't always control the data we need in our applications, and that means we often find ourselves massaging and transforming our data. In this lesson, we'll learn how to transform objects in a declarative way using ramda's evolve function. Assume…

今天再给Android项目工程中的包重命名时出现了这个错误(之前重命名的时候就没有出现,郁闷): An unexpected exception occurred while creating a change object. see the error log for more details 效果如下图所示: 之后google百度各种找,最后在stackoverflow上找到以一个帖子: http://stackoverflow.com/questions/6465127/rename-an…

今天再给Android项目工程中的包重命名时出现了这个错误(之前重命名的时候就没有出现,郁闷):An unexpected exception occurred while creating a change object. see the error log for more details 效果如下图所示: 之后google百度各种找,最后在stackoverflow上找到以一个帖子:http://stackoverflow.com/questions/6465127/rename-andr…

change object keys & UpperCase & LowerCase .toLocaleUpperCase(); && .toLocaleLowerCase(); "use strict"; /** * * @author xgqfrms * @license MIT * @copyright xgqfrms * @created 2018.12.24 * @modified 2018.12.24 * * @description Uti…

In this lesson, we'll look at how we can use Ramda's invoker and constructNfunctions to take methods of an object and turn them into reusable utility functions that are curried and accept their object as the last argument. We'll convert a dot-chained…

In this lesson, we’ll use a Maybe to safely operate on properties of an object that could be undefined. We’ll use our initial code as the basis for a prop utility function that can be reused with different objects and various property names. Instead…

When you want to build your logic with small, composable functions you need a functional way to handle conditional logic. You could wrap ternary expressions and if/else statements in functions, handling all of the concerns around data mutation yourse…

The difference between sort, sortBy, sortWith is that: 1. sort: take function as args. 2. sortBy: take prop as args. 3. sortWith: take array of funcs as args. const R = require('ramda'); const {sort, sortBy, sortWith, descend, prop, ascend} = R; cons…