Merge from vscode 79a1f5a5ca0c6c53db617aa1fa5a2396d2caebe2

src/vs/workbench/api/common/extHostLanguages.ts

@@ -6,6 +6,8 @@
 import { MainContext, MainThreadLanguagesShape, IMainContext } from './extHost.protocol';
 import type * as vscode from 'vscode';
 import { ExtHostDocuments } from 'vs/workbench/api/common/extHostDocuments';
+import * as typeConvert from 'vs/workbench/api/common/extHostTypeConverters';
+import { StandardTokenType, Range, Position } from 'vs/workbench/api/common/extHostTypes';
 
 export class ExtHostLanguages {
 
@@ -32,4 +34,31 @@ export class ExtHostLanguages {
 		}
 		return data.document;
 	}
+
+	async tokenAtPosition(document: vscode.TextDocument, position: vscode.Position): Promise<vscode.TokenInformation> {
+		const versionNow = document.version;
+		const pos = typeConvert.Position.from(position);
+		const info = await this._proxy.$tokensAtPosition(document.uri, pos);
+		const defaultRange = {
+			type: StandardTokenType.Other,
+			range: document.getWordRangeAtPosition(position) ?? new Range(position.line, position.character, position.line, position.character)
+		};
+		if (!info) {
+			// no result
+			return defaultRange;
+		}
+		const result = {
+			range: typeConvert.Range.to(info.range),
+			type: typeConvert.TokenType.to(info.type)
+		};
+		if (!result.range.contains(<Position>position)) {
+			// bogous result
+			return defaultRange;
+		}
+		if (versionNow !== document.version) {
+			// concurrent change
+			return defaultRange;
+		}
+		return result;
+	}
 }