Special Attributes

[Pacman99]

Many times there are attributes you want to include in a POP for utility purposes, but they shouldn't be in the end result(after unpopping). There should be some way to mark certain attributes as special.

This could also replace #1 since you can just add extenders in a pop's extension and mark those attributes as "special", so they get removed when unpopping.

p = pop {
  defaults.value = 0;
  extension = self: super: {
    # Mark increment as "special" somehow
    increment = pop { supers = [ self ]; extension = _: _: { value = super.value + 1; }; };
  };
}
unpop (p.increment.increment) => { value = 2; }

or with #7

pop {
  defaults.value = 0;
  extension = self: super: {
    increment = self (self: super: { value = super.value + 1; });
  };
}

cc @fare

[Pacman99]

In terms of the API I'm thinking it could be a list: pop { specialNames = [ "increment" ]; }. And maybe __meta__ and __unpop__ could be part of that list by default, so unpop doesn't have to know about those, it only has to know about the list of special properties.