UniqueList

Extends darsain/list to create a unique list.

Read about limitations here: darsain/list#limitations.

Install

component install darsain/uniquelist

Usage

var UniqueList = require('uniquelist');
var list = new UniqueList(['a', 'a', 'b', 'c', 'c']);
list.join(); // a,b,c
list.push('a');
list.join(); // a,b,c
list.unshift('d');
list.join(); // d,a,b,c,

With custom compare function:

var data = [
	{ id: 'a' },
	{ id: 'b' },
	{ id: 'b' },
	{ id: 'c' }
];
var compare = function compare(a, b) {
	return a.id === b.id;
};
var list = new UniqueList(data, compare);

console.log(list); // { id: 'a' }, { id: 'b' }, { id: 'c' }

API

UniqueList([array], [compareFunction])

UniqueList constructor. new keyword is optional.

[array]

Array, or an array-like like object to create a UniqueList from.

Can be Array, List, NodeList, arguments, ... everything that looks like { 0: 'foo', length: 1 }.

If you want to have a UniqueList of objects and comparing should be property based, pass the custom compare function to the argument below.

[compareFunction]

Function for comparing 2 items. Receives 2 arguments. Has to return true when items match, false otherwise.

Example:

function compareFunction(a, b) {
	return a.id === b.id;
}

Inherits all methods from List

Methods documented below are either new, or vary from their previous behavior.

#compare(a, b)

Current compare function. Compares 2 items and returns true when they match, false otherwise.

By default uses strict equals === to compare items. You can specify your own compare function by passing it as a 2nd argument to constructor.

#indexOf(item)

Uses #compare() to find an item in a list. Returns an item index, or -1 when not found.

#push(item1, ..., itemN)

Appends new unique items to a list, ignoring duplicates. Uses #compare() for matching items.

#unshift(item1, ..., itemN)

Prepends new unique items to a list, ignoring duplicates. Uses #compare() for matching items.

Testing

To run tests:

component install --dev
component build --dev

And open test/index.html

License

MIT

darsain / uniquelist