xset

Subclass of JavaScript's built-in Set with extra methods.

Usage:

Install:

install --save @gjmcn/xset

The module has a single named export: XSet.

Methods

Use any Set methods as well as:

| Method | Description | Return | |:---|:---|:---| | copy() | Shallow copy. xs.copy() is equivalent to new XSet(xs). | xset | | adds(iterable) | Add each element of iterable to the xset. | xset | | deletes(iterable) | Delete each element of iterable from the xset. | xset | | filter(f, returnArray) | Each element is passed to the function f; if f returns a truthy value, the element is included in the result. If returnArray is truthy, filter returns a new array, otherwise returns a new xset. | xset orarray | | map(f, returnArray) | Each element is passed to the function f; the returned values are collected in a new array (if returnArray is truthy) or a new xset. | xset orarray | | count(f) | Each element is passed to the function f; count returns the number of times that f returns a truthy value. | number | | find(f) | Each element is passed to the function f; the first time f returns a truthy value, the corresponding element is returned. find returns undefined if no element produces a truthy value. | any | | every(f) | Each element is passed to the function f; if f returns a truthy value every time, every returns true — and returns false otherwise. | boolean | | some(f) | Each element is passed to the function f; the first time f returns a truthy value, some returns true. If f returns a falsy value every time, some returns false. | boolean | | first() | First element of the set, or undefined if the set is empty. | any | | difference(iterable1, iterable2, ...) | Returns a new xset containing every element in the calling xset that is not in any of the passed iterables. | xset | | intersection(iterable1, iterable2, ...) | Returns a new xset containing every element that appears in the calling xset and all of the passed iterables. The order of elements in the returned xset matches their order in the calling xset. | xset | | union(iterable1, iterable2, ...) | Returns a new xset containing every element that appears in the calling xset or any of the passed iterables. The order of elements in the returned xset is based on their first occurrence in the calling xset and iterables. | xset |

Example

const s = new XSet([3, 4, 5]);   // XSet {3, 4, 5}
s.add(10);                       // XSet {3, 4, 5, 10}
s.adds([20, 30]);                // XSet {3, 4, 5, 10, 20, 30}

s.filter(e => e < 15);           // new Xset {3, 4, 5, 10}
s.intersection([0, 5, 10, 15]);  // new XSet {5, 10}