Comparers

This library contains some comparison functions.

Installation

npm install --save @gmjs/comparers

Usage

import { compareNumberAsc } from '@gmjs/comparers';

const array = [3, 1, 2];
array.sort(compareNumberAsc());
console.log(array);
// [1, 2, 3]

API Listing

Number

• compareNumberAsc - Creates a comparison function which can be used to sort a number array in ascending order.
• compareNumberDesc - Creates a comparison function which can be used to sort a number array in descending order.
• compareByNumberAsc - Creates a comparison function which can be used to sort an array of items of arbitrary type, by first applying a mapper function returning a number, then sorting by the number in ascending order.
• compareByNumberDesc - Creates a comparison function which can be used to sort an array of items of arbitrary type, by first applying a mapper function returning a number, then sorting by the number in descending order.

String

• compareStringAsc - Creates a comparison function which can be used to sort a string array in ascending order.
• compareStringDesc - Creates a comparison function which can be used to sort a string array in descending order.
• compareByStringAsc - Creates a comparison function which can be used to sort an array of items of arbitrary type, by first applying a mapper function returning a string, then sorting by the string in ascending order.
• compareByStringDesc - Creates a comparison function which can be used to sort an array of items of arbitrary type, by first applying a mapper function returning a string, then sorting by the string in descending order.

API

Number

compareNumberAsc

Creates a comparison function which can be used to sort a number array in ascending order.

import { compareNumberAsc } from '@gmjs/comparers';

const array = [3, 1, 2];
array.sort(compareNumberAsc());
console.log(array);
// [1, 2, 3]

compareNumberDesc

Creates a comparison function which can be used to sort a number array in descending order.

import { compareNumberDesc } from '@gmjs/comparers';

const array = [3, 1, 2];
array.sort(compareNumberDesc());
console.log(array);
// [3, 2, 1]

compareByNumberAsc

Creates a comparison function which can be used to sort an array of items of arbitrary type.

The sort is done by applying a mapper function (first parameter) which returns a number. The comparison is done based on the number returned by the mapper function, in ascending order.

import { compareByNumberAsc } from '@gmjs/comparers';

const array = [{ value: 3 }, { value: 1 }, { value: 2 }];
array.sort(compareByNumberAsc((item) => item.value));
console.log(array);
// [{ value: 1 }, { value: 2 }, { value: 3 }]

compareByNumberDesc

Creates a comparison function which can be used to sort an array of items of arbitrary type.

The sort is done by applying a mapper function (first parameter) which returns a number. The comparison is done based on the number returned by the mapper function, in descending order.

import { compareByNumberDesc } from '@gmjs/comparers';

const array = [{ value: 3 }, { value: 1 }, { value: 2 }];
array.sort(compareByNumberDesc((item) => item.value));
console.log(array);
// [{ value: 3 }, { value: 2 }, { value: 1 }]

String

compareStringAsc

Creates a comparison function which can be used to sort a string array in ascending order.

Accepts an optional options parameter of type CompareStringOptions.

import { compareStringAsc } from '@gmjs/comparers';

const array = ['c', 'a', 'b'];
array.sort(compareStringAsc());
console.log(array);
// ['a', 'b', 'c']

compareStringDesc

Creates a comparison function which can be used to sort a string array in descending order.

Accepts an optional options parameter of type CompareStringOptions.

import { compareStringDesc } from '@gmjs/comparers';

const array = ['c', 'a', 'b'];
array.sort(compareStringDesc());
console.log(array);
// ['c', 'b', 'a']

compareByStringAsc

Creates a comparison function which can be used to sort an array of items of arbitrary type.

The sort is done by applying a mapper function (first parameter) which returns a string. The comparison is done based on the string returned by the mapper function, in ascending order.

Accepts an optional options parameter of type CompareStringOptions.

import { compareByStringAsc } from '@gmjs/comparers';

const array = [{ value: 'c' }, { value: 'a' }, { value: 'b' }];
array.sort(compareByStringAsc((item) => item.value));
console.log(array);
// [{ value: 'a' }, { value: 'b' }, { value: 'c' }]

compareByStringDesc

Creates a comparison function which can be used to sort an array of items of arbitrary type.

The sort is done by applying a mapper function (first parameter) which returns a string. The comparison is done based on the string returned by the mapper function, in descending order.

Accepts an optional options parameter of type CompareStringOptions.

import { compareByStringDesc } from '@gmjs/comparers';

const array = [{ value: 'c' }, { value: 'a' }, { value: 'b' }];
array.sort(compareByStringDesc((item) => item.value));
console.log(array);
// [{ value: 'c' }, { value: 'b' }, { value: 'a' }]

Types

CompareStringOptions

If unspecified, the default are as follows:

• locale: 'en'
• sensitivity: 'case'
• caseFirst: 'upper'

For description of options, check out:

• locale
• sensitivity
• caseFirst

type CompareStringSensivity = 'base' | 'accent' | 'case' | 'variant';
type CompareStringCaseFirst = 'upper' | 'lower' | 'none';

interface CompareStringOptions {
  readonly locale?: string;
  readonly sensitivity?: CompareStringSensivity;
  readonly caseFirst?: CompareStringCaseFirst;
}