forked from zhurui/management
38 lines
1.4 KiB
JavaScript
38 lines
1.4 KiB
JavaScript
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var baseCreate = require('./_baseCreate'),
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isObject = require('./isObject');
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/**
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* Creates a function that produces an instance of `Ctor` regardless of
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* whether it was invoked as part of a `new` expression or by `call` or `apply`.
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*
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* @private
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* @param {Function} Ctor The constructor to wrap.
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* @returns {Function} Returns the new wrapped function.
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*/
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function createCtor(Ctor) {
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return function() {
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// Use a `switch` statement to work with class constructors. See
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// http://ecma-international.org/ecma-262/7.0/#sec-ecmascript-function-objects-call-thisargument-argumentslist
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// for more details.
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var args = arguments;
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switch (args.length) {
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case 0: return new Ctor;
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case 1: return new Ctor(args[0]);
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case 2: return new Ctor(args[0], args[1]);
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case 3: return new Ctor(args[0], args[1], args[2]);
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case 4: return new Ctor(args[0], args[1], args[2], args[3]);
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case 5: return new Ctor(args[0], args[1], args[2], args[3], args[4]);
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case 6: return new Ctor(args[0], args[1], args[2], args[3], args[4], args[5]);
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case 7: return new Ctor(args[0], args[1], args[2], args[3], args[4], args[5], args[6]);
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}
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var thisBinding = baseCreate(Ctor.prototype),
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result = Ctor.apply(thisBinding, args);
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// Mimic the constructor's `return` behavior.
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// See https://es5.github.io/#x13.2.2 for more details.
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return isObject(result) ? result : thisBinding;
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};
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}
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module.exports = createCtor;
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