--- /dev/null
+var Map = require('./es6.map')
+ , $export = require('./_export')
+ , shared = require('./_shared')('metadata')
+ , store = shared.store || (shared.store = new (require('./es6.weak-map')));
+
+var getOrCreateMetadataMap = function(target, targetKey, create){
+ var targetMetadata = store.get(target);
+ if(!targetMetadata){
+ if(!create)return undefined;
+ store.set(target, targetMetadata = new Map);
+ }
+ var keyMetadata = targetMetadata.get(targetKey);
+ if(!keyMetadata){
+ if(!create)return undefined;
+ targetMetadata.set(targetKey, keyMetadata = new Map);
+ } return keyMetadata;
+};
+var ordinaryHasOwnMetadata = function(MetadataKey, O, P){
+ var metadataMap = getOrCreateMetadataMap(O, P, false);
+ return metadataMap === undefined ? false : metadataMap.has(MetadataKey);
+};
+var ordinaryGetOwnMetadata = function(MetadataKey, O, P){
+ var metadataMap = getOrCreateMetadataMap(O, P, false);
+ return metadataMap === undefined ? undefined : metadataMap.get(MetadataKey);
+};
+var ordinaryDefineOwnMetadata = function(MetadataKey, MetadataValue, O, P){
+ getOrCreateMetadataMap(O, P, true).set(MetadataKey, MetadataValue);
+};
+var ordinaryOwnMetadataKeys = function(target, targetKey){
+ var metadataMap = getOrCreateMetadataMap(target, targetKey, false)
+ , keys = [];
+ if(metadataMap)metadataMap.forEach(function(_, key){ keys.push(key); });
+ return keys;
+};
+var toMetaKey = function(it){
+ return it === undefined || typeof it == 'symbol' ? it : String(it);
+};
+var exp = function(O){
+ $export($export.S, 'Reflect', O);
+};
+
+module.exports = {
+ store: store,
+ map: getOrCreateMetadataMap,
+ has: ordinaryHasOwnMetadata,
+ get: ordinaryGetOwnMetadata,
+ set: ordinaryDefineOwnMetadata,
+ keys: ordinaryOwnMetadataKeys,
+ key: toMetaKey,
+ exp: exp
+};
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