Function parse_sorting_order

crates/gitql-parser/src/parse_ordering.rs:65–107

(
    tokens: &[Token],
    position: &mut usize,
)

}

fn parse_sorting_order(
    tokens: &[Token],
    position: &mut usize,
) -> Result<SortingOrder, Box<Diagnostic>> {
    let mut sorting_order = SortingOrder::Ascending;
    if *position >= tokens.len() {
        return Ok(sorting_order);
    }

    // Parse `ASC` or `DESC`
    if is_asc_or_desc(&tokens[*position]) {
        if tokens[*position].kind == TokenKind::Descending {
            sorting_order = SortingOrder::Descending;
        }

        // Consume `ASC or DESC` keyword
        *position += 1;
        return Ok(sorting_order);
    }

    // Parse `USING <Operator>`
    if tokens[*position].kind == TokenKind::Using {
        // Consume `USING` keyword
        *position += 1;

        if *position < tokens.len() && is_order_by_using_operator(&tokens[*position]) {
            if tokens[*position].kind == TokenKind::Greater {
                sorting_order = SortingOrder::Descending;
            }

            // Consume `> or <` keyword
            *position += 1;
            return Ok(sorting_order);
        }

        return Err(Diagnostic::error("Expect `>` or `<` after `USING` keyword")
            .with_location(tokens[*position - 1].location)
            .as_boxed());
    }

    // Return default sorting order
    Ok(sorting_order)
}

fn parse_order_by_nulls_policy(
    tokens: &[Token],