Function resolve_function_arguments

datafusion/expr/src/arguments.rs:63–84

Resolves function arguments, handling named and positional notation. This function validates and reorders arguments to match the function's parameter names when named arguments are used. # Rules - All positional arguments must come before named arguments - Named arguments can be in any order after positional arguments - Parameter names follow SQL identifier rules: unquoted names are case-insensi

(
    param_names: &[String],
    args: Vec<Expr>,
    arg_names: Vec<Option<ArgumentName>>,
)

/// Returns: [Expr(10), Expr(20), Expr(30)]
/// ```
pub fn resolve_function_arguments(
    param_names: &[String],
    args: Vec<Expr>,
    arg_names: Vec<Option<ArgumentName>>,
) -> Result<Vec<Expr>> {
    if args.len() != arg_names.len() {
        return plan_err!(
            "Internal error: args length ({}) != arg_names length ({})",
            args.len(),
            arg_names.len()
        );
    }

    // Check if all arguments are positional (fast path)
    if arg_names.iter().all(|name| name.is_none()) {
        return Ok(args);
    }

    validate_argument_order(&arg_names)?;

    reorder_named_arguments(param_names, args, arg_names)
}

/// Validates that positional arguments come before named arguments
fn validate_argument_order(arg_names: &[Option<ArgumentName>]) -> Result<()> {