You can not select more than 25 topics
			Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
		
		
		
		
		
			
		
			
				
					
					
						
							163 lines
						
					
					
						
							3.2 KiB
						
					
					
				
			
		
		
	
	
							163 lines
						
					
					
						
							3.2 KiB
						
					
					
				| /**
 | |
|  * Mnemonist DefaultMap
 | |
|  * =====================
 | |
|  *
 | |
|  * JavaScript implementation of a default map that will return a constructed
 | |
|  * value any time one tries to access an inexisting key. It's quite similar
 | |
|  * to python's defaultdict.
 | |
|  */
 | |
| 
 | |
| /**
 | |
|  * DefaultMap.
 | |
|  *
 | |
|  * @constructor
 | |
|  */
 | |
| function DefaultMap(factory) {
 | |
|   if (typeof factory !== 'function')
 | |
|     throw new Error('mnemonist/DefaultMap.constructor: expecting a function.');
 | |
| 
 | |
|   this.items = new Map();
 | |
|   this.factory = factory;
 | |
|   this.size = 0;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * Method used to clear the structure.
 | |
|  *
 | |
|  * @return {undefined}
 | |
|  */
 | |
| DefaultMap.prototype.clear = function() {
 | |
| 
 | |
|   // Properties
 | |
|   this.items.clear();
 | |
|   this.size = 0;
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * Method used to get the value set for given key. If the key does not exist,
 | |
|  * the value will be created using the provided factory.
 | |
|  *
 | |
|  * @param  {any} key - Target key.
 | |
|  * @return {any}
 | |
|  */
 | |
| DefaultMap.prototype.get = function(key) {
 | |
|   var value = this.items.get(key);
 | |
| 
 | |
|   if (typeof value === 'undefined') {
 | |
|     value = this.factory(key, this.size);
 | |
|     this.items.set(key, value);
 | |
|     this.size++;
 | |
|   }
 | |
| 
 | |
|   return value;
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * Method used to get the value set for given key. If the key does not exist,
 | |
|  * a value won't be created.
 | |
|  *
 | |
|  * @param  {any} key - Target key.
 | |
|  * @return {any}
 | |
|  */
 | |
| DefaultMap.prototype.peek = function(key) {
 | |
|   return this.items.get(key);
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * Method used to set a value for given key.
 | |
|  *
 | |
|  * @param  {any} key   - Target key.
 | |
|  * @param  {any} value - Value.
 | |
|  * @return {DefaultMap}
 | |
|  */
 | |
| DefaultMap.prototype.set = function(key, value) {
 | |
|   this.items.set(key, value);
 | |
|   this.size = this.items.size;
 | |
| 
 | |
|   return this;
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * Method used to test the existence of a key in the map.
 | |
|  *
 | |
|  * @param  {any} key   - Target key.
 | |
|  * @return {boolean}
 | |
|  */
 | |
| DefaultMap.prototype.has = function(key) {
 | |
|   return this.items.has(key);
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * Method used to delete target key.
 | |
|  *
 | |
|  * @param  {any} key   - Target key.
 | |
|  * @return {boolean}
 | |
|  */
 | |
| DefaultMap.prototype.delete = function(key) {
 | |
|   var deleted = this.items.delete(key);
 | |
| 
 | |
|   this.size = this.items.size;
 | |
| 
 | |
|   return deleted;
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * Method used to iterate over each of the key/value pairs.
 | |
|  *
 | |
|  * @param  {function}  callback - Function to call for each item.
 | |
|  * @param  {object}    scope    - Optional scope.
 | |
|  * @return {undefined}
 | |
|  */
 | |
| DefaultMap.prototype.forEach = function(callback, scope) {
 | |
|   scope = arguments.length > 1 ? scope : this;
 | |
| 
 | |
|   this.items.forEach(callback, scope);
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * Iterators.
 | |
|  */
 | |
| DefaultMap.prototype.entries = function() {
 | |
|   return this.items.entries();
 | |
| };
 | |
| 
 | |
| DefaultMap.prototype.keys = function() {
 | |
|   return this.items.keys();
 | |
| };
 | |
| 
 | |
| DefaultMap.prototype.values = function() {
 | |
|   return this.items.values();
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * Attaching the #.entries method to Symbol.iterator if possible.
 | |
|  */
 | |
| if (typeof Symbol !== 'undefined')
 | |
|   DefaultMap.prototype[Symbol.iterator] = DefaultMap.prototype.entries;
 | |
| 
 | |
| /**
 | |
|  * Convenience known methods.
 | |
|  */
 | |
| DefaultMap.prototype.inspect = function() {
 | |
|   return this.items;
 | |
| };
 | |
| 
 | |
| if (typeof Symbol !== 'undefined')
 | |
|   DefaultMap.prototype[Symbol.for('nodejs.util.inspect.custom')] = DefaultMap.prototype.inspect;
 | |
| 
 | |
| /**
 | |
|  * Typical factories.
 | |
|  */
 | |
| DefaultMap.autoIncrement = function() {
 | |
|   var i = 0;
 | |
| 
 | |
|   return function() {
 | |
|     return i++;
 | |
|   };
 | |
| };
 | |
| 
 | |
| /**
 | |
|  * Exporting.
 | |
|  */
 | |
| module.exports = DefaultMap;
 |