bug#63861: [PATCH] pp.el: New "pretty printing" code

[Juri Linkov <juri@linkov.net>]

>> When tried on emoji-labels.el, at the end it failed with
>>
>>   (scan-error "Containing expression ends prematurely" 255866 255867)
>
> Hmm... when I do
>
>     rm lisp/international/emoji-labels.el
>     make
>
> the file is rebuilt correctly.
> Could you give more details about how you got the above?

With (setq debug-on-error t) when point is at the beginning of this line:

  (defconst emoji--labels '(("Smileys"

typing 'C-u C-M-q' gives the error:

  Debugger entered--Lisp error: (scan-error "Containing expression ends prematurely" 9739 9740)
    pp-region(522 9447)
    pp-region(521 9448)
    pp-buffer()
    indent-pp-sexp((4))
    funcall-interactively(indent-pp-sexp (4))
    command-execute(indent-pp-sexp)

I can send the file, but all its parens are balanced.