Function opt_span_range 

pub fn opt_span_range(
    start: GrammarSpan<'_>,
    end: GrammarSpan<'_>,
) -> Option<Span>

Like opt_span but takes a start/end range using exclusive end semantics.

Replace span: Some(to_parser_span_range(start, end)) with span: opt_span_range(start, end).