anchor.diff:        in
         imap' 0;
   
  -
  -  # Map and concatenate the result.
  +  /**
  +   * Map and concatenate the result.
  +   */
     concatMap = f: list: concatLists (map f list);
   
  -
  -  # Flatten the argument into a single list; that is, nested lists are
  -  # spliced into the top-level lists.  E.g., `flatten [1 [2 [3] 4] 5]
  -  # == [1 2 3 4 5]' and `flatten 1 == [1]'.
  +  /**
  +   * Flatten the argument into a single list; that is, nested lists are
  +   * spliced into the top-level lists.  E.g., `flatten [1 [2 [3] 4] 5]
  +   * == [1 2 3 4 5]' and `flatten 1 == [1]'.
  +   */
     flatten = x:
       if isList x then
         foldl' (x: y: x ++ (flatten y)) [ ] x
       else
         [ x ];
   
  -
     # Remove elements equal to 'e' from a list.  Useful for buildInputs.
     remove = e: filter (x: x != e);
   
  -
  -  # Find the sole element in the list matching the specified
  -  # predicate, returns `default' if no such element exists, or
  -  # `multiple' if there are multiple matching elements.
  +  /**
  +   * Find the sole element in the list matching the specified
  +   * predicate, returns `default' if no such element exists, or
  +   * `multiple' if there are multiple matching elements.
  +   */
     findSingle = pred: default: multiple: list:
       let
         found = filter pred list; len = length found;
  
positive.code:     in
      fold' 0;
  
    # Left fold: `fold op nul [x_1 x_2 ... x_n] == op (... (op (op nul
    # x_1) x_2) ... x_n)'.
    foldl = op: nul: list:
      let
        len = length list;
  
negative.code:       in
        take' 0;
  
    /**
     * Remove the first (at most) N elements of a list.
     */
    drop =
      if builtins ? genList then
        count: list: sublist count (length list) list
  