Macro interoptopus::indented

macro_rules! indented {
    ($w : expr, [$($i : pat) +], $x : expr, $($param : expr), *) => { ... };
    ($w : expr, [$($i : pat) +], $x : expr) => { ... };
    ($w : expr, $x : expr, $($param : expr), *) => { ... };
    ($w : expr, $x : expr) => { ... };
}

Writes a line of code, possibly with multiple indentations. Used in backends.