Emit code locations to kernels if supplied

Author: lionel-

extensions/positron-r/src/session.ts

@@ -203,9 +203,15 @@ export class RSession implements positron.LanguageRuntimeSession, vscode.Disposa
 		throw new Error(`Debugging is not supported in R sessions`);
 	}
 
-	execute(code: string, id: string, mode: positron.RuntimeCodeExecutionMode, errorBehavior: positron.RuntimeErrorBehavior): void {
+	execute(
+		code: string,
+		id: string,
+		mode: positron.RuntimeCodeExecutionMode,
+		errorBehavior: positron.RuntimeErrorBehavior,
+		codeLocation?: vscode.Location,
+	): void {
 		if (this._kernel) {
-			this._kernel.execute(code, id, mode, errorBehavior);
+			this._kernel.execute(code, id, mode, errorBehavior, codeLocation);
 		} else {
 			throw new Error(`Cannot execute '${code}'; kernel not started`);
 		}

extensions/positron-supervisor/src/KallichoreSession.ts

@@ -8,6 +8,7 @@ import * as positron from 'positron';
 import * as os from 'os';
 import * as path from 'path';
 import * as fs from 'fs';
+import * as typesConverters from './jupyter/TypesConverters';
 import { CommBackendMessage, JupyterKernelExtra, JupyterKernelSpec, JupyterLanguageRuntimeSession, JupyterSession, Comm } from './positron-supervisor';
 import { ActiveSession, ConnectionInfo, DefaultApi, InterruptMode, NewSession, RestartSession, StartupEnvironment, Status, VarAction, VarActionType } from './kcclient/api';
 import { JupyterMessage } from './jupyter/JupyterMessage';
@@ -693,10 +694,13 @@ export class KallichoreSession implements JupyterLanguageRuntimeSession {
 	 * @param mode The execution mode
 	 * @param errorBehavior What to do if an error occurs
 	 */
-	execute(code: string,
+	execute(
+		code: string,
 		id: string,
 		mode: positron.RuntimeCodeExecutionMode,
-		errorBehavior: positron.RuntimeErrorBehavior): void {
+		errorBehavior: positron.RuntimeErrorBehavior,
+		codeLocation?: vscode.Location,
+	): void {
 
 		// Translate the parameters into a Jupyter execute request
 		const request: JupyterExecuteRequest = {
@@ -708,6 +712,10 @@ export class KallichoreSession implements JupyterLanguageRuntimeSession {
 			stop_on_error: errorBehavior === positron.RuntimeErrorBehavior.Stop,
 		};
 
+		if (codeLocation) {
+			request.positron = { code_location: typesConverters.JupyterPositronLocation.from(codeLocation, code) };
+		}
+
 		// Create and send the execute request
 		const execute = new ExecuteRequest(id, request);
 		this.sendRequest(execute).then((reply) => {

extensions/positron-supervisor/src/jupyter/ExecuteRequest.ts

@@ -6,6 +6,7 @@
 import { JupyterChannel } from './JupyterChannel';
 import { JupyterDisplayData } from './JupyterDisplayData';
 import { JupyterMessageType } from './JupyterMessageType.js';
+import { JupyterPositronLocation, JupyterPositronRange } from './JupyterPositronTypes';
 import { JupyterRequest } from './JupyterRequest';
 
 
@@ -41,6 +42,14 @@ export interface JupyterExecuteRequest {
 
 	/** Whether the kernel should stop the execution queue when an error occurs */
 	stop_on_error: boolean;
+
+	/** Positron extension */
+	positron?: JupyterPositronExecuteRequest;
+}
+
+export interface JupyterPositronExecuteRequest {
+	/** Location of `code`. Encoded in UTF-16 offsets. */
+	code_location?: JupyterPositronLocation;
 }
 
 /**

extensions/positron-supervisor/src/jupyter/JupyterPositronTypes.ts

@@ -0,0 +1,22 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (C) 2025 Posit Software, PBC. All rights reserved.
+ *  Licensed under the Elastic License 2.0. See LICENSE.txt for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+export interface JupyterPositronLocation {
+	uri: string;
+	range: JupyterPositronRange;
+}
+
+export interface JupyterPositronRange {
+	start: JupyterPositronPosition;
+	end: JupyterPositronPosition;
+}
+
+// See https://jupyter-client.readthedocs.io/en/stable/messaging.html#cursor-pos-unicode-note
+// regarding choice of offset in unicode points
+export interface JupyterPositronPosition {
+	line: number;
+	/** Column offset in unicode points */
+	character: number;
+}

extensions/positron-supervisor/src/jupyter/TypesConverters.ts

@@ -0,0 +1,61 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (C) 2025 Posit Software, PBC. All rights reserved.
+ *  Licensed under the Elastic License 2.0. See LICENSE.txt for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as vscode from 'vscode';
+import * as PositronTypes from './JupyterPositronTypes';
+
+export namespace JupyterPositronLocation {
+	export function from(location: vscode.Location, text: string): PositronTypes.JupyterPositronLocation {
+		return {
+			uri: location.uri.toString(),
+			range: JupyterPositronRange.from(location.range, text),
+		};
+	}
+}
+
+export namespace JupyterPositronRange {
+	export function from(range: vscode.Range, text: string): PositronTypes.JupyterPositronRange {
+		return {
+			start: JupyterPositronPosition.from(range.start, text),
+			end: JupyterPositronPosition.from(range.end, text),
+		};
+	}
+}
+
+export namespace JupyterPositronPosition {
+	export function from(position: vscode.Position, text: string): PositronTypes.JupyterPositronPosition {
+		return {
+			line: position.line,
+			character: codePointOffsetFromUtf16Index(text, position.character),
+		};
+	}
+}
+
+
+export function codePointOffsetFromUtf16Index(text: string, utf16Index: number): number {
+	if (utf16Index <= 0) {
+		return 0;
+	}
+
+	let offset = 0;
+	let i = 0;
+
+	while (i < text.length && i < utf16Index) {
+		const codePoint = text.codePointAt(i);
+		if (codePoint === undefined) {
+			break;
+		}
+
+		// Advance by 2 for surrogate pairs (code points > 0xFFFF), 1 otherwise
+		i += codePoint > 0xFFFF ? 2 : 1;
+
+		// Only count this code point if we haven't passed the target index
+		if (i <= utf16Index) {
+			++offset;
+		}
+	}
+
+	return offset;
+}