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197 lines
4.5 KiB
197 lines
4.5 KiB
/**
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* Mnemonist FuzzyMultiMap
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* ========================
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*
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* Same as the fuzzy map but relying on a MultiMap rather than a Map.
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*/
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var MultiMap = require('./multi-map.js'),
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forEach = require('obliterator/foreach');
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var identity = function(x) {
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return x;
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};
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/**
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* FuzzyMultiMap.
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*
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* @constructor
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* @param {array|function} descriptor - Hash functions descriptor.
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* @param {function} Container - Container to use.
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*/
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function FuzzyMultiMap(descriptor, Container) {
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this.items = new MultiMap(Container);
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this.clear();
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if (Array.isArray(descriptor)) {
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this.writeHashFunction = descriptor[0];
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this.readHashFunction = descriptor[1];
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}
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else {
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this.writeHashFunction = descriptor;
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this.readHashFunction = descriptor;
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}
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if (!this.writeHashFunction)
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this.writeHashFunction = identity;
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if (!this.readHashFunction)
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this.readHashFunction = identity;
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if (typeof this.writeHashFunction !== 'function')
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throw new Error('mnemonist/FuzzyMultiMap.constructor: invalid hash function given.');
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if (typeof this.readHashFunction !== 'function')
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throw new Error('mnemonist/FuzzyMultiMap.constructor: invalid hash function given.');
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}
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/**
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* Method used to clear the structure.
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*
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* @return {undefined}
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*/
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FuzzyMultiMap.prototype.clear = function() {
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this.items.clear();
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// Properties
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this.size = 0;
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this.dimension = 0;
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};
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/**
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* Method used to add an item to the index.
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*
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* @param {any} item - Item to add.
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* @return {FuzzyMultiMap}
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*/
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FuzzyMultiMap.prototype.add = function(item) {
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var key = this.writeHashFunction(item);
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this.items.set(key, item);
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this.size = this.items.size;
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this.dimension = this.items.dimension;
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return this;
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};
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/**
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* Method used to set an item in the index using the given key.
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*
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* @param {any} key - Key to use.
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* @param {any} item - Item to add.
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* @return {FuzzyMultiMap}
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*/
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FuzzyMultiMap.prototype.set = function(key, item) {
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key = this.writeHashFunction(key);
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this.items.set(key, item);
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this.size = this.items.size;
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this.dimension = this.items.dimension;
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return this;
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};
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/**
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* Method used to retrieve an item from the index.
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*
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* @param {any} key - Key to use.
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* @return {any}
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*/
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FuzzyMultiMap.prototype.get = function(key) {
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key = this.readHashFunction(key);
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return this.items.get(key);
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};
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/**
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* Method used to test the existence of an item in the map.
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*
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* @param {any} key - Key to check.
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* @return {boolean}
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*/
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FuzzyMultiMap.prototype.has = function(key) {
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key = this.readHashFunction(key);
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return this.items.has(key);
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};
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/**
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* Method used to iterate over each of the index's values.
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*
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* @param {function} callback - Function to call for each item.
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* @param {object} scope - Optional scope.
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* @return {undefined}
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*/
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FuzzyMultiMap.prototype.forEach = function(callback, scope) {
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scope = arguments.length > 1 ? scope : this;
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this.items.forEach(function(value) {
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callback.call(scope, value, value);
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});
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};
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/**
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* Method returning an iterator over the index's values.
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*
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* @return {FuzzyMultiMapIterator}
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*/
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FuzzyMultiMap.prototype.values = function() {
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return this.items.values();
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};
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/**
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* Attaching the #.values method to Symbol.iterator if possible.
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*/
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if (typeof Symbol !== 'undefined')
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FuzzyMultiMap.prototype[Symbol.iterator] = FuzzyMultiMap.prototype.values;
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/**
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* Convenience known method.
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*/
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FuzzyMultiMap.prototype.inspect = function() {
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var array = Array.from(this);
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Object.defineProperty(array, 'constructor', {
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value: FuzzyMultiMap,
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enumerable: false
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});
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return array;
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};
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if (typeof Symbol !== 'undefined')
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FuzzyMultiMap.prototype[Symbol.for('nodejs.util.inspect.custom')] = FuzzyMultiMap.prototype.inspect;
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/**
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* Static @.from function taking an arbitrary iterable & converting it into
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* a structure.
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*
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* @param {Iterable} iterable - Target iterable.
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* @param {array|function} descriptor - Hash functions descriptor.
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* @param {function} Container - Container to use.
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* @param {boolean} useSet - Whether to use #.set or #.add
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* @return {FuzzyMultiMap}
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*/
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FuzzyMultiMap.from = function(iterable, descriptor, Container, useSet) {
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if (arguments.length === 3) {
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if (typeof Container === 'boolean') {
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useSet = Container;
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Container = Array;
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}
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}
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var map = new FuzzyMultiMap(descriptor, Container);
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forEach(iterable, function(value, key) {
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if (useSet)
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map.set(key, value);
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else
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map.add(value);
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});
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return map;
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};
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/**
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* Exporting.
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*/
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module.exports = FuzzyMultiMap;
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