Macro html 

macro_rules! html {
    ($name:ident $([ $($an:tt = $av:expr),* $(,)? ])? { $($tk:tt)* }) => { ... };
    (! $parent:ident $name:ident $([$($args:tt)*])? { $($tk:tt)* } $($rest:tt)*) => { ... };
    (! $parent:ident $name:ident $([$($an:ident = $av:expr),*])? ; $($rest:tt)*) => { ... };
    (! $parent:ident $name:ident = $val:expr ; $($rest:tt)*) => { ... };
    (! $parent:ident $s:literal ; $($rest:tt)*) => { ... };
    (! $parent:ident { $e:expr } $($rest:tt)*) => { ... };
    (! $parent:ident ? { $e:expr } $($rest:tt)*) => { ... };
    (! $parent:ident [ $e:expr ] $($rest:tt)*) => { ... };
    (! $parent:ident) => { ... };
    (@ $i:ident) => { ... };
    (@ $s:literal) => { ... };
}