anchor.diff:      data))
   
   (defun read-all! (path) 
  -  "Reads the data from the file at `PATH` and returns it as a string.
  +  "Reads the data from the file at PATH and returns it as a string.
      Returns nil if it failed.
   
      ### Example
  
positive.code:   (write-all-mode! path true false data))
  
  (defun append-lines! (path data)
    "Appends the lines (list of strings) `data` to the file at `PATH`.
     Creates a new file if it doesn't exist.
     Returns true if it succeeded or false if it failed.
  
  
negative.code:   (append-all! path (concat data "\n")))
  
  (defun append-bytes! (path data)
    "Appends the bytes (list of numbers) `data` to the file at PATH.
     Creates a new file if it doesn't exist.
     Returns true if it succeeded or false if it failed.
  
  