implemented frontend including separate message system; started to implement backend

yjs-poll/node_modules/lib0/observable.js

@@ -0,0 +1,161 @@
+/**
+ * Observable class prototype.
+ *
+ * @module observable
+ */
+
+import * as map from './map.js'
+import * as set from './set.js'
+import * as array from './array.js'
+
+/**
+ * Handles named events.
+ * @experimental
+ *
+ * This is basically a (better typed) duplicate of Observable, which will replace Observable in the
+ * next release.
+ *
+ * @template {{[key in keyof EVENTS]: function(...any):void}} EVENTS
+ */
+export class ObservableV2 {
+  constructor () {
+    /**
+     * Some desc.
+     * @type {Map<string, Set<any>>}
+     */
+    this._observers = map.create()
+  }
+
+  /**
+   * @template {keyof EVENTS & string} NAME
+   * @param {NAME} name
+   * @param {EVENTS[NAME]} f
+   */
+  on (name, f) {
+    map.setIfUndefined(this._observers, /** @type {string} */ (name), set.create).add(f)
+    return f
+  }
+
+  /**
+   * @template {keyof EVENTS & string} NAME
+   * @param {NAME} name
+   * @param {EVENTS[NAME]} f
+   */
+  once (name, f) {
+    /**
+     * @param  {...any} args
+     */
+    const _f = (...args) => {
+      this.off(name, /** @type {any} */ (_f))
+      f(...args)
+    }
+    this.on(name, /** @type {any} */ (_f))
+  }
+
+  /**
+   * @template {keyof EVENTS & string} NAME
+   * @param {NAME} name
+   * @param {EVENTS[NAME]} f
+   */
+  off (name, f) {
+    const observers = this._observers.get(name)
+    if (observers !== undefined) {
+      observers.delete(f)
+      if (observers.size === 0) {
+        this._observers.delete(name)
+      }
+    }
+  }
+
+  /**
+   * Emit a named event. All registered event listeners that listen to the
+   * specified name will receive the event.
+   *
+   * @todo This should catch exceptions
+   *
+   * @template {keyof EVENTS & string} NAME
+   * @param {NAME} name The event name.
+   * @param {Parameters<EVENTS[NAME]>} args The arguments that are applied to the event listener.
+   */
+  emit (name, args) {
+    // copy all listeners to an array first to make sure that no event is emitted to listeners that are subscribed while the event handler is called.
+    return array.from((this._observers.get(name) || map.create()).values()).forEach(f => f(...args))
+  }
+
+  destroy () {
+    this._observers = map.create()
+  }
+}
+
+/* c8 ignore start */
+/**
+ * Handles named events.
+ *
+ * @deprecated
+ * @template N
+ */
+export class Observable {
+  constructor () {
+    /**
+     * Some desc.
+     * @type {Map<N, any>}
+     */
+    this._observers = map.create()
+  }
+
+  /**
+   * @param {N} name
+   * @param {function} f
+   */
+  on (name, f) {
+    map.setIfUndefined(this._observers, name, set.create).add(f)
+  }
+
+  /**
+   * @param {N} name
+   * @param {function} f
+   */
+  once (name, f) {
+    /**
+     * @param  {...any} args
+     */
+    const _f = (...args) => {
+      this.off(name, _f)
+      f(...args)
+    }
+    this.on(name, _f)
+  }
+
+  /**
+   * @param {N} name
+   * @param {function} f
+   */
+  off (name, f) {
+    const observers = this._observers.get(name)
+    if (observers !== undefined) {
+      observers.delete(f)
+      if (observers.size === 0) {
+        this._observers.delete(name)
+      }
+    }
+  }
+
+  /**
+   * Emit a named event. All registered event listeners that listen to the
+   * specified name will receive the event.
+   *
+   * @todo This should catch exceptions
+   *
+   * @param {N} name The event name.
+   * @param {Array<any>} args The arguments that are applied to the event listener.
+   */
+  emit (name, args) {
+    // copy all listeners to an array first to make sure that no event is emitted to listeners that are subscribed while the event handler is called.
+    return array.from((this._observers.get(name) || map.create()).values()).forEach(f => f(...args))
+  }
+
+  destroy () {
+    this._observers = map.create()
+  }
+}
+/* c8 ignore end */