knowledge/node_modules/eventemitter3/dist/eventemitter3.umd.js

(function (global, factory) {
	typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
	typeof define === 'function' && define.amd ? define(factory) :
	(global = typeof globalThis !== 'undefined' ? globalThis : global || self, global.EventEmitter3 = factory());
})(this, (function () { 'use strict';

	function getDefaultExportFromCjs (x) {
		return x && x.__esModule && Object.prototype.hasOwnProperty.call(x, 'default') ? x['default'] : x;
	}

	var eventemitter3 = {exports: {}};

	var hasRequiredEventemitter3;

	function requireEventemitter3 () {
		if (hasRequiredEventemitter3) return eventemitter3.exports;
		hasRequiredEventemitter3 = 1;
		(function (module) {

			var has = Object.prototype.hasOwnProperty
			  , prefix = '~';

			/**
			 * Constructor to create a storage for our `EE` objects.
			 * An `Events` instance is a plain object whose properties are event names.
			 *
			 * @constructor
			 * @private
			 */
			function Events() {}

			//
			// We try to not inherit from `Object.prototype`. In some engines creating an
			// instance in this way is faster than calling `Object.create(null)` directly.
			// If `Object.create(null)` is not supported we prefix the event names with a
			// character to make sure that the built-in object properties are not
			// overridden or used as an attack vector.
			//
			if (Object.create) {
			  Events.prototype = Object.create(null);

			  //
			  // This hack is needed because the `__proto__` property is still inherited in
			  // some old browsers like Android 4, iPhone 5.1, Opera 11 and Safari 5.
			  //
			  if (!new Events().__proto__) prefix = false;
			}

			/**
			 * Representation of a single event listener.
			 *
			 * @param {Function} fn The listener function.
			 * @param {*} context The context to invoke the listener with.
			 * @param {Boolean} [once=false] Specify if the listener is a one-time listener.
			 * @constructor
			 * @private
			 */
			function EE(fn, context, once) {
			  this.fn = fn;
			  this.context = context;
			  this.once = once || false;
			}

			/**
			 * Add a listener for a given event.
			 *
			 * @param {EventEmitter} emitter Reference to the `EventEmitter` instance.
			 * @param {(String|Symbol)} event The event name.
			 * @param {Function} fn The listener function.
			 * @param {*} context The context to invoke the listener with.
			 * @param {Boolean} once Specify if the listener is a one-time listener.
			 * @returns {EventEmitter}
			 * @private
			 */
			function addListener(emitter, event, fn, context, once) {
			  if (typeof fn !== 'function') {
			    throw new TypeError('The listener must be a function');
			  }

			  var listener = new EE(fn, context || emitter, once)
			    , evt = prefix ? prefix + event : event;

			  if (!emitter._events[evt]) emitter._events[evt] = listener, emitter._eventsCount++;
			  else if (!emitter._events[evt].fn) emitter._events[evt].push(listener);
			  else emitter._events[evt] = [emitter._events[evt], listener];

			  return emitter;
			}

			/**
			 * Clear event by name.
			 *
			 * @param {EventEmitter} emitter Reference to the `EventEmitter` instance.
			 * @param {(String|Symbol)} evt The Event name.
			 * @private
			 */
			function clearEvent(emitter, evt) {
			  if (--emitter._eventsCount === 0) emitter._events = new Events();
			  else delete emitter._events[evt];
			}

			/**
			 * Minimal `EventEmitter` interface that is molded against the Node.js
			 * `EventEmitter` interface.
			 *
			 * @constructor
			 * @public
			 */
			function EventEmitter() {
			  this._events = new Events();
			  this._eventsCount = 0;
			}

			/**
			 * Return an array listing the events for which the emitter has registered
			 * listeners.
			 *
			 * @returns {Array}
			 * @public
			 */
			EventEmitter.prototype.eventNames = function eventNames() {
			  var names = []
			    , events
			    , name;

			  if (this._eventsCount === 0) return names;

			  for (name in (events = this._events)) {
			    if (has.call(events, name)) names.push(prefix ? name.slice(1) : name);
			  }

			  if (Object.getOwnPropertySymbols) {
			    return names.concat(Object.getOwnPropertySymbols(events));
			  }

			  return names;
			};

			/**
			 * Return the listeners registered for a given event.
			 *
			 * @param {(String|Symbol)} event The event name.
			 * @returns {Array} The registered listeners.
			 * @public
			 */
			EventEmitter.prototype.listeners = function listeners(event) {
			  var evt = prefix ? prefix + event : event
			    , handlers = this._events[evt];

			  if (!handlers) return [];
			  if (handlers.fn) return [handlers.fn];

			  for (var i = 0, l = handlers.length, ee = new Array(l); i < l; i++) {
			    ee[i] = handlers[i].fn;
			  }

			  return ee;
			};

			/**
			 * Return the number of listeners listening to a given event.
			 *
			 * @param {(String|Symbol)} event The event name.
			 * @returns {Number} The number of listeners.
			 * @public
			 */
			EventEmitter.prototype.listenerCount = function listenerCount(event) {
			  var evt = prefix ? prefix + event : event
			    , listeners = this._events[evt];

			  if (!listeners) return 0;
			  if (listeners.fn) return 1;
			  return listeners.length;
			};

			/**
			 * Calls each of the listeners registered for a given event.
			 *
			 * @param {(String|Symbol)} event The event name.
			 * @returns {Boolean} `true` if the event had listeners, else `false`.
			 * @public
			 */
			EventEmitter.prototype.emit = function emit(event, a1, a2, a3, a4, a5) {
			  var evt = prefix ? prefix + event : event;

			  if (!this._events[evt]) return false;

			  var listeners = this._events[evt]
			    , len = arguments.length
			    , args
			    , i;

			  if (listeners.fn) {
			    if (listeners.once) this.removeListener(event, listeners.fn, undefined, true);

			    switch (len) {
			      case 1: return listeners.fn.call(listeners.context), true;
			      case 2: return listeners.fn.call(listeners.context, a1), true;
			      case 3: return listeners.fn.call(listeners.context, a1, a2), true;
			      case 4: return listeners.fn.call(listeners.context, a1, a2, a3), true;
			      case 5: return listeners.fn.call(listeners.context, a1, a2, a3, a4), true;
			      case 6: return listeners.fn.call(listeners.context, a1, a2, a3, a4, a5), true;
			    }

			    for (i = 1, args = new Array(len -1); i < len; i++) {
			      args[i - 1] = arguments[i];
			    }

			    listeners.fn.apply(listeners.context, args);
			  } else {
			    var length = listeners.length
			      , j;

			    for (i = 0; i < length; i++) {
			      if (listeners[i].once) this.removeListener(event, listeners[i].fn, undefined, true);

			      switch (len) {
			        case 1: listeners[i].fn.call(listeners[i].context); break;
			        case 2: listeners[i].fn.call(listeners[i].context, a1); break;
			        case 3: listeners[i].fn.call(listeners[i].context, a1, a2); break;
			        case 4: listeners[i].fn.call(listeners[i].context, a1, a2, a3); break;
			        default:
			          if (!args) for (j = 1, args = new Array(len -1); j < len; j++) {
			            args[j - 1] = arguments[j];
			          }

			          listeners[i].fn.apply(listeners[i].context, args);
			      }
			    }
			  }

			  return true;
			};

			/**
			 * Add a listener for a given event.
			 *
			 * @param {(String|Symbol)} event The event name.
			 * @param {Function} fn The listener function.
			 * @param {*} [context=this] The context to invoke the listener with.
			 * @returns {EventEmitter} `this`.
			 * @public
			 */
			EventEmitter.prototype.on = function on(event, fn, context) {
			  return addListener(this, event, fn, context, false);
			};

			/**
			 * Add a one-time listener for a given event.
			 *
			 * @param {(String|Symbol)} event The event name.
			 * @param {Function} fn The listener function.
			 * @param {*} [context=this] The context to invoke the listener with.
			 * @returns {EventEmitter} `this`.
			 * @public
			 */
			EventEmitter.prototype.once = function once(event, fn, context) {
			  return addListener(this, event, fn, context, true);
			};

			/**
			 * Remove the listeners of a given event.
			 *
			 * @param {(String|Symbol)} event The event name.
			 * @param {Function} fn Only remove the listeners that match this function.
			 * @param {*} context Only remove the listeners that have this context.
			 * @param {Boolean} once Only remove one-time listeners.
			 * @returns {EventEmitter} `this`.
			 * @public
			 */
			EventEmitter.prototype.removeListener = function removeListener(event, fn, context, once) {
			  var evt = prefix ? prefix + event : event;

			  if (!this._events[evt]) return this;
			  if (!fn) {
			    clearEvent(this, evt);
			    return this;
			  }

			  var listeners = this._events[evt];

			  if (listeners.fn) {
			    if (
			      listeners.fn === fn &&
			      (!once || listeners.once) &&
			      (!context || listeners.context === context)
			    ) {
			      clearEvent(this, evt);
			    }
			  } else {
			    for (var i = 0, events = [], length = listeners.length; i < length; i++) {
			      if (
			        listeners[i].fn !== fn ||
			        (once && !listeners[i].once) ||
			        (context && listeners[i].context !== context)
			      ) {
			        events.push(listeners[i]);
			      }
			    }

			    //
			    // Reset the array, or remove it completely if we have no more listeners.
			    //
			    if (events.length) this._events[evt] = events.length === 1 ? events[0] : events;
			    else clearEvent(this, evt);
			  }

			  return this;
			};

			/**
			 * Remove all listeners, or those of the specified event.
			 *
			 * @param {(String|Symbol)} [event] The event name.
			 * @returns {EventEmitter} `this`.
			 * @public
			 */
			EventEmitter.prototype.removeAllListeners = function removeAllListeners(event) {
			  var evt;

			  if (event) {
			    evt = prefix ? prefix + event : event;
			    if (this._events[evt]) clearEvent(this, evt);
			  } else {
			    this._events = new Events();
			    this._eventsCount = 0;
			  }

			  return this;
			};

			//
			// Alias methods names because people roll like that.
			//
			EventEmitter.prototype.off = EventEmitter.prototype.removeListener;
			EventEmitter.prototype.addListener = EventEmitter.prototype.on;

			//
			// Expose the prefix.
			//
			EventEmitter.prefixed = prefix;

			//
			// Allow `EventEmitter` to be imported as module namespace.
			//
			EventEmitter.EventEmitter = EventEmitter;

			//
			// Expose the module.
			//
			{
			  module.exports = EventEmitter;
			} 
		} (eventemitter3));
		return eventemitter3.exports;
	}

	var eventemitter3Exports = requireEventemitter3();
	var index = /*@__PURE__*/getDefaultExportFromCjs(eventemitter3Exports);

	return index;

}));