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node_modules/is-callable/index.js 1.09 KB
aaac7fed   liuqimichale   add
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  'use strict';
  
  var fnToStr = Function.prototype.toString;
  
  var constructorRegex = /^\s*class\b/;
  var isES6ClassFn = function isES6ClassFunction(value) {
  	try {
  		var fnStr = fnToStr.call(value);
  		return constructorRegex.test(fnStr);
  	} catch (e) {
  		return false; // not a function
  	}
  };
  
  var tryFunctionObject = function tryFunctionToStr(value) {
  	try {
  		if (isES6ClassFn(value)) { return false; }
  		fnToStr.call(value);
  		return true;
  	} catch (e) {
  		return false;
  	}
  };
  var toStr = Object.prototype.toString;
  var fnClass = '[object Function]';
  var genClass = '[object GeneratorFunction]';
  var hasToStringTag = typeof Symbol === 'function' && typeof Symbol.toStringTag === 'symbol';
  
  module.exports = function isCallable(value) {
  	if (!value) { return false; }
  	if (typeof value !== 'function' && typeof value !== 'object') { return false; }
  	if (typeof value === 'function' && !value.prototype) { return true; }
  	if (hasToStringTag) { return tryFunctionObject(value); }
  	if (isES6ClassFn(value)) { return false; }
  	var strClass = toStr.call(value);
  	return strClass === fnClass || strClass === genClass;
  };