Function parse_order_by_statement

crates/gitql-parser/src/parse_ordering.rs:16–63

(
    context: &mut ParserContext,
    env: &mut Environment,
    tokens: &[Token],
    position: &mut usize,
)

use crate::token::TokenKind;

pub(crate) fn parse_order_by_statement(
    context: &mut ParserContext,
    env: &mut Environment,
    tokens: &[Token],
    position: &mut usize,
) -> Result<Statement, Box<Diagnostic>> {
    // Consume `ORDER` keyword
    *position += 1;

    context.inside_order_by = true;

    // Consume `BY` keyword
    consume_token_or_error(
        tokens,
        position,
        TokenKind::By,
        "Expect keyword `BY` after keyword `ORDER",
    )?;

    let mut arguments: Vec<Box<dyn Expr>> = vec![];
    let mut sorting_orders: Vec<SortingOrder> = vec![];
    let mut null_ordering_policies: Vec<NullsOrderPolicy> = vec![];

    loop {
        let argument = parse_expression(context, env, tokens, position)?;
        let sorting_order = parse_sorting_order(tokens, position)?;
        let null_ordering_policy = parse_order_by_nulls_policy(tokens, position, &sorting_order)?;

        arguments.push(argument);
        sorting_orders.push(sorting_order);
        null_ordering_policies.push(null_ordering_policy);

        if is_current_token(tokens, position, TokenKind::Comma) {
            // Consume `,` keyword
            *position += 1;
        } else {
            break;
        }
    }

    context.inside_order_by = false;

    Ok(Statement::OrderBy(OrderByStatement {
        arguments,
        sorting_orders,
        nulls_order_policies: null_ordering_policies,
    }))
}

fn parse_sorting_order(
    tokens: &[Token],