RLSearchParams, as it will unnecessarily escape
            // characters, such as '/'.
            url.search = "f=" + file +
                "&s=" + start_line + "." + end_line +
                "&e=" + end_line + "." + end_column;
            window.history.replaceState(null, "", url.toString());
        };

        let before = (line, col, span) => {
            if (line < span[0]) { return true; }
            if (line == span[0]) { return col < span[1]; }
            return false;
        };

        l