@nemoinho/comparator-js


Compare complex objects with ease.
This library provides a simple API to create complex comparators and keep them understandable for humans.

> The comparator is heavily inspired by the Comparator from Java.

Usage

The library provides some simple functions and can be easily extended to complex comparators:

``typescript
import { comparing } from "@nemoinho/comparator-js";

type Person = {
name: string;
originCountry: string;
}

const people = [/ people here /]

const comparator =
comparing("originCountry")
.thenComparing("name");

// create a new sorted list
comparator.sort(people);

// or sort existing list in place
people.sort(comparator);
`

API

The library provides the following functions:

comparing(valueExtractor, keyComparator?): Comparator

Create a comparator which compares objects of Type T.

valueExtractor: The valueExtractor can either be a field-name of T or a function which extracts a value from a given object T.

keyComparator: An optional comparator to compare the extracted value.
The default comparator is capable of comparing string and numbers, all other types will be considered equal!

---

comparingSimpleString(keyComparator?): Comparator
comparingSimpleNumber(keyComparator?): Comparator

Create a comparator to compare string/numbers instead of objects.

keyComparator: An optional comparator to compare the extracted value.
The default comparator is capable of comparing string and numbers, all other types will be considered equal!

---

Comparator.thenComparing(valueExtractor, keyComparator?): Comparator

Chains another comparison onto the comparator, note that this is only executed if the previous comparisons resulted in equal objects.

valueExtractor: The valueExtractor can either be a field-name of T or a function which extracts a value from a given object T.

keyComparator: An optional comparator to compare the extracted value.
The default comparator is capable of comparing string and numbers, all other types will be considered equal!

---

Comparator.reverse(): Comparator

Reverses the result of the current comparator.

---

Comparator.thenComparingReverse(valueExtractor, keyComparator?): Comparator

A convenience method which combines thenComparing() and reverse().

---

Comparator.sort(list): Array`

This method returns a sorted version of the given list, which is sorted by this comparator.