Function parse_set_query

crates/gitql-parser/src/parser.rs:121–177

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

}

fn parse_set_query(
    env: &mut Environment,
    tokens: &[Token],
    position: &mut usize,
) -> Result<Query, Box<Diagnostic>> {
    let len = tokens.len();
    let mut context = ParserContext::default();

    // Consume Set keyword
    *position += 1;

    if !is_current_token_with_condition(tokens, position, |token| {
        matches!(token.kind, TokenKind::GlobalVariable(_))
    }) {
        return Err(Diagnostic::error(
            "Expect Global variable name start with `@` after `SET` keyword",
        )
        .with_location(calculate_safe_location(tokens, *position - 1))
        .as_boxed());
    }

    let name = &tokens[*position].to_string();

    // Consume variable name
    *position += 1;

    if *position >= len || !is_assignment_operator(&tokens[*position]) {
        return Err(
            Diagnostic::error("Expect `=` or `:=` and Value after Variable name")
                .with_location(calculate_safe_location(tokens, *position - 1))
                .as_boxed(),
        );
    }

    // Consume `=` or `:=` token
    *position += 1;

    let aggregations_count_before = context.aggregations.len();
    let value = parse_expression(&mut context, env, tokens, position)?;
    let has_aggregations = context.aggregations.len() != aggregations_count_before;

    // Until supports sub queries, aggregation value can't be stored in variables
    if has_aggregations {
        return Err(
            Diagnostic::error("Aggregation value can't be assigned to global variable")
                .with_location(calculate_safe_location(tokens, *position - 1))
                .as_boxed(),
        );
    }

    env.define_global(name.to_string(), value.expr_type());

    Ok(Query::GlobalVariableDecl(GlobalVariableDeclQuery {
        name: name.to_string(),
        value,
    }))
}