@geffencode/linqscript

Project Title

A basic implementation of LINQ methods for Typescript.

Installation

$ npm install @geffencode/linqscript

Usage/Examples

import { AsLinq, LINQArray} from "@geffencode/linqscript";

interface Person {
    id: number;
    name: string;
    age: number;
    city: string;
    hobbies: string[]
}

const persons: Person[] = myService.getPersons();

// By declaring a new LINQArray
const linqArray = new LINQArray<Person>(...persons);
const names = linqArray.Select(p => p.name); // ['John Doe', 'Jane Doe', 'Jane Smith', ...]

// Copying an existing array as LINQArray
const ids = AsLinq(persons).Select(p => p.id); // [1, 2, 3, ...]

// Getting the hobbies of people older than 30 for a city
const hobbies = linqArray.Where(p => p.age > 30 && p.city == 'Mogadishu')
                                  .SelectMany(p => p.hobbies)
                                  .Distinct(); // Remove duplicates

// Id, name and age of all people that play competitive chess boxing in Thimphu
// ordered by age descending, returning a regular array.
const chessboxers = linqArray.Where(p => p.city === 'Thimphu')
                            .Select(({id, name, age}) => ({id, name, age}))
                            .OrderByDescending(p => p.age)
                            .ToArray();

// Get all persons grouped by city
const byCity = linqArray.GroupBy(p => p.city);

API Reference

Method	Argument	Return	Description
Add	item: T	None	Adds an item to the end of the array.
AddRange	arr: T[]	None	Adds multiple items to the end of the array.
GroupBy	predicate: (item: T) => K	Record<K, T[]>	Groups the elements in the array by the specified key selector.
Select	predicate: (item: T) => K	LINQArray	Projects each element of the array to a new form using the specified selector function.
Where	predicate: (item: T) => boolean	LINQArray	Filters the elements of the array based on a predicate function.
First	predicate?: (item: T) => boolean	T or undefined	Returns the first element of the array that satisfies a specified condition, or undefined if no such element is found.
FirstOrDefault	predicate?: (item: T) => boolean	T or undefined	Returns the first element of the array that satisfies a specified condition, or undefined if no such element is found.
SelectMany	predicate: (item: T) => K[]	LINQArray	Projects each element of the array to a sequence and flattens the resulting sequences into one LINQArray.
Distinct	None	LINQArray	Returns a new LINQArray containing only the distinct elements of the original array.
DistinctBy	predicate: (item: T) => K	LINQArray	Returns a new LINQArray containing only the distinct elements of the original array, determined by the specified key selector function.
OrderBy	predicate: (item: T) => K	LINQArray	Sorts the elements of the array in ascending order according to the specified key selector function.
OrderByDescending	predicate: (item: T) => K	LINQArray	Sorts the elements of the array in descending order based on the specified predicate.
Any	predicate?: (item: T) => boolean	boolean	Determines whether any element of the array satisfies the specified predicate.
Take	i: number	LINQArray	Returns a new array that contains the specified number of elements from the start of the array.
Skip	i: number	LINQArray	Bypasses a specified number of elements in the array and returns the remaining elements.
ToArray	None	T[]	Copies the elements of the LINQArray to a new Array.
_log	None	LINQArray	Logs the current array to the console and returns it.