What is @lumino/coreutils?
@lumino/coreutils is a utility library that provides a collection of core utilities for JavaScript applications. It includes functions for handling data structures, managing signals, and working with JSON data, among other things.
What are @lumino/coreutils's main functionalities?
Data Structures
The ArrayExt module provides utility functions for working with arrays. In this example, the findFirstIndex function is used to find the first index in the array where the value is greater than 3.
const { ArrayExt } = require('@lumino/coreutils');
let data = [1, 2, 3, 4, 5];
let index = ArrayExt.findFirstIndex(data, value => value > 3);
console.log(index); // Output: 3
JSON Utilities
The JSONExt module provides utility functions for working with JSON data. In this example, the deepEqual function is used to compare two JSON objects for deep equality.
const { JSONExt } = require('@lumino/coreutils');
let obj1 = { a: 1, b: 2 };
let obj2 = { a: 1, b: 2 };
let isEqual = JSONExt.deepEqual(obj1, obj2);
console.log(isEqual); // Output: true
Signal Management
The Signal module provides a way to manage signals and slots, similar to the observer pattern. In this example, a signal is created and connected to a slot that logs the received signal.
const { Signal } = require('@lumino/coreutils');
class MyObject {
constructor() {
this._signal = new Signal(this);
}
get signal() {
return this._signal;
}
}
let obj = new MyObject();
obj.signal.connect((sender, args) => {
console.log('Signal received:', args);
});
obj.signal.emit('Hello, world!'); // Output: Signal received: Hello, world!
Other packages similar to @lumino/coreutils
lodash
Lodash is a modern JavaScript utility library delivering modularity, performance, and extras. It provides a wide range of utility functions for common programming tasks, such as manipulating arrays, objects, and strings. Compared to @lumino/coreutils, Lodash offers a broader set of utilities but does not include signal management.
underscore
Underscore is a JavaScript library that provides a whole mess of useful functional programming helpers without extending any built-in objects. It offers similar functionalities to Lodash but with a different API. Like Lodash, it does not include signal management features found in @lumino/coreutils.
eventemitter3
EventEmitter3 is a high-performance EventEmitter for Node.js and the browser. It provides a simple and efficient way to manage events and listeners. While it focuses on event management, it does not offer the array and JSON utilities provided by @lumino/coreutils.