Prepare for next level macro
Prepare for next level macro

The actual macro we want is more like

`pick![4, Command::Left, 1 Command::Right]`

Favoring left to right 4 to 1. In order to allow this we renamed the
soon to be private macro pickWeighted.

darwins-challenge/moonlander-ast-rust,darwins-challenge/moonlander-ast-rust