anchor.diff:  
      ### Example:
      ```cl
  -   > (init (range 1 10))
  +   > (init (range :from 1 :to 10))
      out = '(1 2 3 4 5 6 7 8 9)
      ```"
     (assert-type! xs list)
  
positive.code:    ```"
    (foldl append '() xss))
  
  (defun range (start end)
    "Build a list from START to END.
  
     ### Example:
     ```cl
     > (range 1 10)
     out = (1 2 3 4 5 6 7 8 9 10)
     ```"
    (let* [(out '())]
      (for i start end 1
        (push-cdr! out i))
      out))
  
  (defun reverse (xs)
    "Reverse the list XS, using the accumulator ACC.
  
     ### Example:
     ```cl
     > (reverse (range 1 10))
     out = (10 9 8 7 6 5 4 3 2 1)
     ```"
    (let* [(out '())]
  
negative.code:    thing."
  
  (import base (defun defmacro when unless let* set-idx!
                get-idx for gensym -or slice /= %
                pretty print error tostring  -and
                unpack debug if n + - >= > = ! with
                apply and progn .. * while <= < or))
  (import base)
  (import lua/table)
  (import type (nil? list? empty? assert-type! exists? falsey? eq? neq? type))
  (import lua/math (min max huge))
  
  (defun car (x)
    "Return the first element present in the list X. This function operates
  