Macro comet::extract_update

macro_rules! extract_update {
    (
        $self:ident,
        $msg:ident,
        $type:ty,
        {
            {
                {
                    if
                        ($($predicate:tt)*)
                        { $($e:tt)* }

                    $($rest:tt)*
                }
                [$($expanded:tt)*]
            }
        }
    ) => { ... };
    (
        $self:ident,
        $msg:ident,
        $type:ty,
        {
            {
                {
                    for
                        $($predicate:ident),+ in ($($iter:tt)*)
                        { $($e:tt)* }

                    $($rest:tt)*
                }
                [$($expanded:tt)*]
            }
        }
    ) => { ... };
    (
        $self:ident,
        $msg:ident,
        $type:ty,
        {
            {
                {
                    $tag:ident $(#$id_name:ident)? $(.$class_name:ident)*
                        $([$($attr_name:ident : {$($attr_value:tt)*} ),*])?
                        $($(@$ev:ident : {$($evcode:tt)*} ),+ )?
                        $(={ $($binding:tt)* })?
                        { $($e:tt)* }

                    $($rest:tt)*
                }
                [$($expanded:tt)*]
            }
        }
    ) => { ... };
    (
        $self:ident,
        $msg:ident,
        $type:ty,
        {
            {
                {
                    @{$($comp:tt)+}
                    $($rest:tt)*
                }
                [$($expanded:tt)*]
            }
        }
    ) => { ... };
    (
        $self:ident,
        $msg:ident,
        $type:ty,
        {
            {
                {
                    { $($code:tt)* }
                    $($rest:tt)*
                }
                [$($expanded:tt)*]
            }
        }
    ) => { ... };
    () => { ... };
    (
        $self:ident,
        $msg:ident,
        $type:ty,
        {
            {
                {}
                [$({ {$($name:tt)*},  $($code:tt)* })*]
                $({$($binding:tt)*})?
            }
        }
    ) => { ... };
    (
        $self:ident,
        $msg:ident,
        $type:ty,
        $( $e:tt )*
    ) => { ... };
}