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					28 lines
				
				799 B
			
		
		
			
		
	
	
					28 lines
				
				799 B
			| 
											11 months ago
										 | 'use strict'; | ||
|  | var $ = require('../internals/export'); | ||
|  | var aWeakMap = require('../internals/a-weak-map'); | ||
|  | var WeakMapHelpers = require('../internals/weak-map-helpers'); | ||
|  | 
 | ||
|  | var get = WeakMapHelpers.get; | ||
|  | var has = WeakMapHelpers.has; | ||
|  | var set = WeakMapHelpers.set; | ||
|  | 
 | ||
|  | // `WeakMap.prototype.emplace` method
 | ||
|  | // https://github.com/tc39/proposal-upsert
 | ||
|  | $({ target: 'WeakMap', proto: true, real: true, forced: true }, { | ||
|  |   emplace: function emplace(key, handler) { | ||
|  |     var map = aWeakMap(this); | ||
|  |     var value, inserted; | ||
|  |     if (has(map, key)) { | ||
|  |       value = get(map, key); | ||
|  |       if ('update' in handler) { | ||
|  |         value = handler.update(value, key, map); | ||
|  |         set(map, key, value); | ||
|  |       } return value; | ||
|  |     } | ||
|  |     inserted = handler.insert(key, map); | ||
|  |     set(map, key, inserted); | ||
|  |     return inserted; | ||
|  |   } | ||
|  | }); |