src/vs/editor/common/services/editorSimpleWorker.ts/MirrorModel/getWordAtPosition
class MirrorModel:	public getWordAtPosition(position: IPosition, wordDefinition: RegExp): Range | null {

		const wordAtText = getWordAtText(
			position.column,
			ensureValidWordDefinition(wordDefinition),
			this._lines[position.lineNumber - 1],
			0
		);

		if (wordAtText) {
			return new Range(position.lineNumber, wordAtText.startColumn, position.lineNumber, wordAtText.endColumn);
		}

		return null;
	}