Macro fluid 

macro_rules! fluid {
    ($expr:expr, {}) => { ... };
    ($expr:expr, { $block:ident$(::<$($typeargs:ty),+>)?($($args:expr),*) { $($children:tt)+ } $($next:tt)* }) => { ... };
    ($expr:expr, { [$($items:tt)+]; $($next:tt)* }) => { ... };
    ($expr:expr, { $command:ident$(::<$($typeargs:ty),+>)?($($args:expr),*); $($next:tt)* }) => { ... };
}

General-purpose macro that allows you to write long method chains as a series of statements. See the crate documentation for more details.