Macro scale 

macro_rules! scale {
    (v=[$x:expr, $y:expr, $z:expr], $($child:expr);+;) => { ... };
    ([$x:expr, $y:expr, $z:expr], $($child:expr);+;) => { ... };
}

Scale an object.

#params

v: Vector of scale factors for x, y, and z axis respectively.

children: A list of Scad objects separated and ending with a semicolon.

expansion: A Scad struct literal.

#patterns

scale!([‘x: f64’, ‘y: f64’, ‘z: f64’], ‘children: Scad’;);

scale!(v=[‘x: f64’, ‘y: f64’, ‘z: f64’], ‘children: Scad’;);