First commit.

Signed-off-by: Chen Xiao <abigwc@gmail.com>

client/node_modules/langium/lib/utils/collections.js

@@ -0,0 +1,195 @@
+/******************************************************************************
+ * Copyright 2021 TypeFox GmbH
+ * This program and the accompanying materials are made available under the
+ * terms of the MIT License, which is available in the project root.
+ ******************************************************************************/
+import { EMPTY_STREAM, Reduction, stream } from './stream.js';
+/**
+ * A multimap is a variation of a Map that has potentially multiple values for every key.
+ */
+export class MultiMap {
+    constructor(elements) {
+        this.map = new Map();
+        if (elements) {
+            for (const [key, value] of elements) {
+                this.add(key, value);
+            }
+        }
+    }
+    /**
+     * The total number of values in the multimap.
+     */
+    get size() {
+        return Reduction.sum(stream(this.map.values()).map(a => a.length));
+    }
+    /**
+     * Clear all entries in the multimap.
+     */
+    clear() {
+        this.map.clear();
+    }
+    /**
+     * Operates differently depending on whether a `value` is given:
+     *  * With a value, this method deletes the specific key / value pair from the multimap.
+     *  * Without a value, all values associated with the given key are deleted.
+     *
+     * @returns `true` if a value existed and has been removed, or `false` if the specified
+     *     key / value does not exist.
+     */
+    delete(key, value) {
+        if (value === undefined) {
+            return this.map.delete(key);
+        }
+        else {
+            const values = this.map.get(key);
+            if (values) {
+                const index = values.indexOf(value);
+                if (index >= 0) {
+                    if (values.length === 1) {
+                        this.map.delete(key);
+                    }
+                    else {
+                        values.splice(index, 1);
+                    }
+                    return true;
+                }
+            }
+            return false;
+        }
+    }
+    /**
+     * Returns an array of all values associated with the given key. If no value exists,
+     * an empty array is returned.
+     *
+     * _Note:_ The returned array is assumed not to be modified. Use the `set` method to add a
+     * value and `delete` to remove a value from the multimap.
+     */
+    get(key) {
+        return this.map.get(key) ?? [];
+    }
+    /**
+     * Returns a stream of all values associated with the given key. If no value exists,
+     * {@link EMPTY_STREAM} is returned.
+     */
+    getStream(key) {
+        const values = this.map.get(key);
+        return values ? stream(values) : EMPTY_STREAM;
+    }
+    /**
+     * Operates differently depending on whether a `value` is given:
+     *  * With a value, this method returns `true` if the specific key / value pair is present in the multimap.
+     *  * Without a value, this method returns `true` if the given key is present in the multimap.
+     */
+    has(key, value) {
+        if (value === undefined) {
+            return this.map.has(key);
+        }
+        else {
+            const values = this.map.get(key);
+            if (values) {
+                return values.indexOf(value) >= 0;
+            }
+            return false;
+        }
+    }
+    /**
+     * Add the given key / value pair to the multimap.
+     */
+    add(key, value) {
+        if (this.map.has(key)) {
+            this.map.get(key).push(value);
+        }
+        else {
+            this.map.set(key, [value]);
+        }
+        return this;
+    }
+    /**
+     * Add the given set of key / value pairs to the multimap.
+     */
+    addAll(key, values) {
+        if (this.map.has(key)) {
+            this.map.get(key).push(...values);
+        }
+        else {
+            this.map.set(key, Array.from(values));
+        }
+        return this;
+    }
+    /**
+     * Invokes the given callback function for every key / value pair in the multimap.
+     */
+    forEach(callbackfn) {
+        this.map.forEach((array, key) => array.forEach(value => callbackfn(value, key, this)));
+    }
+    /**
+     * Returns an iterator of key, value pairs for every entry in the map.
+     */
+    [Symbol.iterator]() {
+        return this.entries().iterator();
+    }
+    /**
+     * Returns a stream of key, value pairs for every entry in the map.
+     */
+    entries() {
+        return stream(this.map.entries())
+            .flatMap(([key, array]) => array.map(value => [key, value]));
+    }
+    /**
+     * Returns a stream of keys in the map.
+     */
+    keys() {
+        return stream(this.map.keys());
+    }
+    /**
+     * Returns a stream of values in the map.
+     */
+    values() {
+        return stream(this.map.values()).flat();
+    }
+    /**
+     * Returns a stream of key, value set pairs for every key in the map.
+     */
+    entriesGroupedByKey() {
+        return stream(this.map.entries());
+    }
+}
+export class BiMap {
+    get size() {
+        return this.map.size;
+    }
+    constructor(elements) {
+        this.map = new Map();
+        this.inverse = new Map();
+        if (elements) {
+            for (const [key, value] of elements) {
+                this.set(key, value);
+            }
+        }
+    }
+    clear() {
+        this.map.clear();
+        this.inverse.clear();
+    }
+    set(key, value) {
+        this.map.set(key, value);
+        this.inverse.set(value, key);
+        return this;
+    }
+    get(key) {
+        return this.map.get(key);
+    }
+    getKey(value) {
+        return this.inverse.get(value);
+    }
+    delete(key) {
+        const value = this.map.get(key);
+        if (value !== undefined) {
+            this.map.delete(key);
+            this.inverse.delete(value);
+            return true;
+        }
+        return false;
+    }
+}
+//# sourceMappingURL=collections.js.map