13 lines
655 B
JavaScript
13 lines
655 B
JavaScript
'use strict';
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var isObject = require('./_is-object')
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, getPrototypeOf = require('./_object-gpo')
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, HAS_INSTANCE = require('./_wks')('hasInstance')
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, FunctionProto = Function.prototype;
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// 19.2.3.6 Function.prototype[@@hasInstance](V)
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if(!(HAS_INSTANCE in FunctionProto))require('./_object-dp').f(FunctionProto, HAS_INSTANCE, {value: function(O){
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if(typeof this != 'function' || !isObject(O))return false;
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if(!isObject(this.prototype))return O instanceof this;
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// for environment w/o native `@@hasInstance` logic enough `instanceof`, but add this:
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while(O = getPrototypeOf(O))if(this.prototype === O)return true;
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return false;
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}}); |