src/vs/editor/contrib/suggest/browser/suggestController.ts/LineSuffix/delta
class LineSuffix:	delta(position: IPosition): number {
		if (this._model.isDisposed() || this._position.lineNumber !== position.lineNumber) {
			// bail out early if things seems fishy
			return 0;
		}
		// read the marker (in case suggest was triggered at line end) or compare
		// the cursor to the line end.
		if (this._marker) {
			const range = this._model.getDecorationRange(this._marker[0]);
			const end = this._model.getOffsetAt(range!.getStartPosition());
			return end - this._model.getOffsetAt(position);
		} else {
			return this._model.getLineMaxColumn(position.lineNumber) - position.column;
		}
	}