Macro html5ever::tree_builder::tag_sets::declare_tag_set_body

macro_rules! declare_tag_set_body {
    ($param:ident = [$supr:ident] - $($tag:tt)+) => { ... };
    ($param:ident = [$supr:ident] + $($tag:tt)+) => { ... };
    ($param:ident = $($tag:tt)+) => { ... };
}