add hw2

node_modules/langium/lib/workspace/ast-node-locator.d.ts

@@ -0,0 +1,37 @@
+/******************************************************************************
+ * 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 type { AstNode } from '../syntax-tree.js';
+/**
+ * Language-specific service for locating an `AstNode` in a document.
+ */
+export interface AstNodeLocator {
+    /**
+     * Creates a path represented by a `string` that identifies an `AstNode` inside its document.
+     * It must be possible to retrieve exactly the same `AstNode` from the document using this path.
+     *
+     * @param node The `AstNode` for which to create the path.
+     * @returns a path represented by a `string` that identifies `node` inside its document.
+     * @see AstNodeLocator.getAstNode
+     */
+    getAstNodePath(node: AstNode): string;
+    /**
+     * Locates an `AstNode` inside another node by following the given path.
+     *
+     * @param node Parent element.
+     * @param path Describes how to locate the `AstNode` inside the given `node`.
+     * @returns The `AstNode` located under the given path, or `undefined` if the path cannot be resolved.
+     * @see AstNodeLocator.getAstNodePath
+     */
+    getAstNode<T extends AstNode = AstNode>(node: AstNode, path: string): T | undefined;
+}
+export declare class DefaultAstNodeLocator implements AstNodeLocator {
+    protected segmentSeparator: string;
+    protected indexSeparator: string;
+    getAstNodePath(node: AstNode): string;
+    protected getPathSegment({ $containerProperty, $containerIndex }: AstNode): string;
+    getAstNode<T extends AstNode = AstNode>(node: AstNode, path: string): T | undefined;
+}
+//# sourceMappingURL=ast-node-locator.d.ts.map