ref: 91f737e4effa109cb22bc1b2000f457fa1ad88db
dir: /TODO/
* Stop comparing strings all the time * Stop copying the entire goal stack into every choicepoint * Stop creating choicepoints when it is not needed * How to implement builtins nicely? * Right now we copy and allocate a lot, but almost never free stuff. * Many builtins should really throw an error, but they just fail for now. * Exceptions (throw, catch) * Modules (I try to do something like SWI prolog for now, but I know there is also an iso standard)