Function parse_case

nodedb-query/src/expr_parse/parser.rs:274–316

(
    tokens: &[Token],
    pos: &mut usize,
    depth: &mut usize,
)

}

fn parse_case(
    tokens: &[Token],
    pos: &mut usize,
    depth: &mut usize,
) -> Result<SqlExpr, ExprParseError> {
    let mut when_thens = Vec::new();
    let mut else_expr = None;

    loop {
        if peek_keyword(tokens, *pos, "WHEN") {
            *pos += 1;
            let cond = parse_expr(tokens, pos, depth)?;
            expect_keyword(tokens, pos, "THEN")?;
            let then = parse_expr(tokens, pos, depth)?;
            when_thens.push((cond, then));
        } else if peek_keyword(tokens, *pos, "ELSE") {
            *pos += 1;
            else_expr = Some(Box::new(parse_expr(tokens, pos, depth)?));
        } else if peek_keyword(tokens, *pos, "END") {
            *pos += 1;
            break;
        } else {
            return Err(ExprParseError::UnexpectedToken {
                found: tokens
                    .get(*pos)
                    .map_or("EOF".to_string(), |t| t.text.clone()),
                pos: *pos,
            });
        }
    }

    if when_thens.is_empty() {
        return Err(ExprParseError::InvalidLiteral {
            detail: "CASE requires at least one WHEN clause".to_string(),
        });
    }

    Ok(SqlExpr::Case {
        operand: None,
        when_thens,
        else_expr,
    })
}

fn parse_arg_list(
    tokens: &[Token],