ludic/docs/language/list/list-pop.md

id	name	category	kind	tokens	sig	tip	order	ns	member
list-pop	List.pop	list	namespace-method	List.pop	List.pop(s) -> T	Remove and return the last element.	5	List	pop

Removes the final element of s and returns it, shortening the slice by one. Together with List.push this makes a slice work as a stack: push to add, pop to take the most recent back off. The slice must be non-empty. Use it to unwind a history, process a work list, or undo the last action.

Parameters:

• s — a non-empty slice

program UndoStack {
  state UndoStackState {
    history: []int = new []int
  }

  handler Undo(undo_stack_st: UndoStackState) phase Update {
    if List.len(undo_stack_st.history) > 0 {
      let last_action = List.pop(undo_stack_st.history)
    }
  }
}