OSet

Ordered Set/Map Data Structure With Extra Functionality

About

OSet is a very small JavaScript library, providing ordered set/map data structures, i.e., data structures which provide set/map functionality where the insertion order of the items is preserved. These types of data structures are important if a collection of items should be hold and it is important to be able to interate over the items in a particular order, too. The OSet/OMap collections are similar to the ECMAScript 6 Set/Map collections, but provide additional functionality like set/map merge/union/intersection/difference and sort operations.

Installation

$ npm install oset

Usage

OSet

OSet is similar to ECMAScript Set, but with additional functionality.

Importing

• import { OSet } from "oset"
  Import OSet (ECMAScript 6 variant).

• var OSet = require("oset").OSet
  Import OSet (CommonJS variant).

Main Operations

• new OSet(): OSet: [O(1)]
  Create a new empty set instance.

• OSet#size(): Number: [O(1)]
  Get number of items in the set.

• OSet#has(val: Object): Boolean: [O(n)]
  Check whether item exists.

• OSet#add(val: Object, toFront?: Boolean): OSet: [O(n)]
  Add value to set. If this item is already stored, ignore it. Else insert as a new item into the set (by default to the end of the list of elements, or, if toFront is true, to the start of the list of elements).

• OSet#del(val: Object): OSet: [O(n)]
  Delete item from set. If no value exists in set an exception is thrown.

Extra Operations

• OSet#clear(): OSet: [O(n)]
  Delete all items under key.

• OSet#values(): Object[]: [O(n)]
  Get the list of values in the set, in insertion order.

• OSet#find(predicate: (val: Object, order: Number) => Boolean, ctx: Object): Object[]: [O(n)]
  Iterate over all values in the set, in insertion order, and call the predicate function for each value. The function receives the item value and the iteration order (starting from zero and steadily increasing). If predicate returns true the value is placed into the result array of items.

• OSet#each(iterator: (val: Object, order: Number) => Void, ctx: Object): Object: [O(n)]
  Iterate over all values in the set, in insertion order, and call the iterator function for each object. The function receives the item value and the iteration order (starting from zero and steadily increasing). The function returns the passed ctx object.

• OSet#merge(other: OSet): OSet: [O(n)]
  Merge all items of other into the set. The merged items are removed from other.

• OSet#union(other: OSet): OSet: [O(n)]
  Return a new set created through the union of the target set and the other set. Both the target and the other set are not modified.

• OSet#intersection(other: OSet): OSet: [O(n)]
  Return a new set created through the intersection of the target set and the other set. Both the target and the other set are not modified.

• OSet#difference(other: OSet): OSet: [O(n)]
  Return a new set created through the difference/complement of the target set and the other set. Both the target and the other set are not modified.

• OSet#sort(compare?: (valA: Object, valB: Object) => Number): OSet: [O(n)]
  Sort all values in-place by comparing them. The optional compare function should return -1 if valA is less than valB, +1 if valA is greater than valB and 0 if valA is equal valB.

OMap

OMap is similar to ECMAScript Map, but with additional functionality.

Importing

• import { OMap } from "oset"
  Import OMap (ECMAScript 6 variant).

• var OMap = require("oset").OMap
  Import OMap (CommonJS variant).

Main Operations

• new OMap(): OMap: [O(1)]
  Create a new empty map instance.

• OMap#size(): Number: [O(1)]
  Get number of items in the map.

• OMap#has(key: String): Boolean: [O(1)]
  Check whether item exists under key.

• OMap#get(key: String): Object: [O(1)]
  Get value of item under key. If no object exists under key the value undefined is returned.

• OMap#set(key: String, val: Object, toFront?: Boolean): OMap: [O(1)]
  Set value of item under key. If there is already an item stored under key, replace its value. Else insert as a new item into the map (by default to the end of the list of elements, or, if toFront is true, to the start of the list of elements).

• OMap#del(key: String): OMap: [O(1)]
  Delete item under key. If no object exists under key an exception is thrown.

Extra Operations

• OMap#clear(): OMap: [O(n)]
  Delete all items under key.

• OMap#keys(): String[]: [O(n)]
  Get the list of keys of all items in the map, in insertion order.

• OMap#values(): Object[]: [O(n)]
  Get the list of values of all items in the map, in insertion order.

• OMap#find(predicate: (val: Object, key: String, order: Number) => Boolean, ctx: Object): Object[]: [O(n)]
  Iterate over all items in the map, in insertion order, and call the predicate function for each object. The function receives the item value, the item key and the iteration order (starting from zero and steadily increasing). If predicate returns true the item is placed into the result array of items.

• OMap#each(iterator: (val: Object, key: String, order: Number) => Void, ctx: Object): Object: [O(n)]
  Iterate over all items in the map, in insertion order, and call the iterator function for each object. The function receives the item value, the item key and the iteration order (starting from zero and steadily increasing). The function returns the passed ctx object.

• OMap#merge(other: OMap): OMap: [O(n)]
  Merge all items of other into the map. The merged items are removed from other.

• OMap#union(other: OMap): OMap: [O(n)]
  Return a new map created through the union of the target map and the other map. Both the target and the other map are not modified.

• OMap#intersection(other: OMap): OMap: [O(n)]
  Return a new map created through the intersection of the target map and the other map. Both the target and the other map are not modified.

• OMap#difference(other: OMap): OMap: [O(n)]
  Return a new map created through the difference/complement of the target map and the other map. Both the target and the other map are not modified.

• OMap#sort(compare?: (keyA: String, keyB: String) => Number): OMap: [O(n)]
  Sort all items in-place by comparing their keys. The optional compare function should return -1 if keyA is less than keyB, +1 if keyA is greater than keyB and 0 if keyA is equal keyB.

Implementation Notice

Although the OSet library is written in ECMAScript 6, it is transpiled to ECMAScript 5 and this way runs in really all(!) current (as of 2015) JavaScript environments, of course.

Internally, the OSet and OMap data structures are based on a managing all items in a ring of double-linked buckets. This allows efficient insertion/deletion operations without special cases.

License

Copyright (c) 2015-2023 Dr. Ralf S. Engelschall (http://engelschall.com/)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.