Fixed #191

Used first code snippets from ClearURLs v2: https://gitlab.com/ClearURLs/core/-/blob/master/src/utils/URLHashParams.ts

core_js/utils/Multimap.js

@@ -0,0 +1,130 @@
+"use strict";
+/*
+ * ClearURLs
+ * Copyright (c) 2017-2022 Kevin Röbert.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * Models a multimap backed by a {@link Set}.
+ */
+class Multimap {
+    constructor() {
+        Object.defineProperty(this, "_map", {
+            enumerable: true,
+            configurable: true,
+            writable: true,
+            value: void 0
+        });
+        Object.defineProperty(this, "_size", {
+            enumerable: true,
+            configurable: true,
+            writable: true,
+            value: void 0
+        });
+        this._size = 0;
+        this._map = new Map();
+    }
+    get size() {
+        return this._size;
+    }
+    get(key) {
+        const values = this._map.get(key);
+        if (values) {
+            return new Set(values);
+        }
+        else {
+            return new Set();
+        }
+    }
+    put(key, value) {
+        let values = this._map.get(key);
+        if (!values) {
+            values = new Set();
+        }
+        const count = values.size;
+        values.add(value);
+        if (values.size === count) {
+            return false;
+        }
+        this._map.set(key, values);
+        this._size++;
+        return true;
+    }
+    has(key) {
+        return this._map.has(key);
+    }
+    hasEntry(key, value) {
+        const values = this._map.get(key);
+        if (!values) {
+            return false;
+        }
+        return values.has(value);
+    }
+    delete(key) {
+        const values = this._map.get(key);
+        if (values && this._map.delete(key)) {
+            this._size -= values.size;
+            return true;
+        }
+        return false;
+    }
+    deleteEntry(key, value) {
+        const values = this._map.get(key);
+        if (values) {
+            if (!values.delete(value)) {
+                return false;
+            }
+            this._size--;
+            return true;
+        }
+        return false;
+    }
+    clear() {
+        this._map.clear();
+        this._size = 0;
+    }
+    entries() {
+        const self = this;
+        function* gen() {
+            for (const [key, values] of self._map.entries()) {
+                for (const value of values) {
+                    yield [key, value];
+                }
+            }
+        }
+        return gen();
+    }
+    values() {
+        const self = this;
+        function* gen() {
+            for (const [, value] of self.entries()) {
+                yield value;
+            }
+        }
+        return gen();
+    }
+    keys() {
+        return this._map.keys();
+    }
+    forEach(callback, thisArg) {
+        for (const [key, value] of this.entries()) {
+            callback.call(thisArg === undefined ? this : thisArg, key, value, this);
+        }
+    }
+    [Symbol.iterator]() {
+        return this.entries();
+    }
+}