Macro captcha_oxide_core::parse_attrs

macro_rules! parse_attrs {
    ($i: ident ($input: ident, $output: ident) { $($k: literal $(: $duplicate: expr)? => $e:expr),* $(,)?  }) => { ... };
    (nested $i: ident ($input: ident, $output: ident) { $($k: literal $(: $duplicate: expr)? => $e:expr),* $(,)?  }) => { ... };
}