First commit.

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

client/node_modules/langium/lib/lsp/declaration-provider.d.ts

@@ -0,0 +1,21 @@
+/******************************************************************************
+ * Copyright 2022 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 { DeclarationParams, LocationLink } from 'vscode-languageserver';
+import type { CancellationToken } from '../utils/cancellation.js';
+import type { MaybePromise } from '../utils/promise-utils.js';
+import type { LangiumDocument } from '../workspace/documents.js';
+/**
+ * Language-specific service for handling go to declaration requests
+ */
+export interface DeclarationProvider {
+    /**
+     * Handle a go to declaration request.
+     * @throws `OperationCancelled` if cancellation is detected during execution
+     * @throws `ResponseError` if an error is detected that should be sent as response to the client
+     */
+    getDeclaration(document: LangiumDocument, params: DeclarationParams, cancelToken?: CancellationToken): MaybePromise<LocationLink[] | undefined>;
+}
+//# sourceMappingURL=declaration-provider.d.ts.map