add hw2

node_modules/langium/lib/lsp/signature-help-provider.js

@@ -0,0 +1,50 @@
+/******************************************************************************
+ * 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 { CancellationToken } from '../utils/cancellation.js';
+import { findLeafNodeAtOffset } from '../utils/cst-utils.js';
+export class AbstractSignatureHelpProvider {
+    provideSignatureHelp(document, params, cancelToken = CancellationToken.None) {
+        const rootNode = document.parseResult.value;
+        const cst = rootNode.$cstNode;
+        if (cst) {
+            const sourceCstNode = findLeafNodeAtOffset(cst, document.textDocument.offsetAt(params.position));
+            if (sourceCstNode) {
+                return this.getSignatureFromElement(sourceCstNode.astNode, cancelToken);
+            }
+        }
+        return undefined;
+    }
+    /**
+     * Override this getter to return the list of triggering characters for your language. To deactivate the signature help, return an empty object.
+     */
+    get signatureHelpOptions() {
+        return {
+            triggerCharacters: ['('],
+            retriggerCharacters: [',']
+        };
+    }
+}
+/**
+ * Merges the SignatureHelpOptions of all languages
+ */
+export function mergeSignatureHelpOptions(options) {
+    const triggerCharacters = [];
+    const retriggerCharacters = [];
+    options.forEach(option => {
+        if (option === null || option === void 0 ? void 0 : option.triggerCharacters) {
+            triggerCharacters.push(...option.triggerCharacters);
+        }
+        if (option === null || option === void 0 ? void 0 : option.retriggerCharacters) {
+            retriggerCharacters.push(...option.retriggerCharacters);
+        }
+    });
+    const mergedOptions = {
+        triggerCharacters: triggerCharacters.length > 0 ? Array.from(new Set(triggerCharacters)).sort() : undefined,
+        retriggerCharacters: retriggerCharacters.length > 0 ? Array.from(new Set(retriggerCharacters)).sort() : undefined
+    };
+    return mergedOptions.triggerCharacters ? mergedOptions : undefined;
+}
+//# sourceMappingURL=signature-help-provider.js.map