type scalar = string | int | float | bool;

function scalar_to_string(scalar $value): string {
    if $value is string {
        $value
    } else if $value is int || $value is float {
        if $value is int {
            Str\format("%d", $value)
        } else {
            Str\format("%.2f", $value)
        }
    }

    $value ? "true" : "false"
}

function is_scalar(mixed $value): bool {
    $value is scalar
}

function as_scalar(mixed $value): scalar {
    $value as scalar
}