From mboxrd@z Thu Jan  1 00:00:00 1970
From: Nicolas Goaziou <mail@nicolasgoaziou.fr>
Subject: Re: Bug: Empty result when Emacs Lisp code block evals to nil [9.0.5
 (release_9.0.5-401-g86ff11 @ /Users/xcy/src/org-mode/lisp/)]
Date: Wed, 05 Apr 2017 10:12:52 +0200
Message-ID: <87shlnz30b.fsf@nicolasgoaziou.fr>
References: <m2zig0dv5w.fsf@xuchunyang.me>
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In-Reply-To: <m2zig0dv5w.fsf@xuchunyang.me> (Chunyang Xu's message of "Sat, 01
	Apr 2017 23:06:35 +0800")
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To: Chunyang Xu <mail@xuchunyang.me>
Cc: emacs-orgmode@gnu.org

Chunyang Xu <mail@xuchunyang.me> writes:

> I notice that if the result is nil during executing emacs-lisp code
> block, org simply displays a empty #+RESULT block. For example,
>
> #+BEGIN_SRC emacs-lisp
> t
> #+END_SRC
>
>
> #+RESULTS: : t
>
> #+BEGIN_SRC emacs-lisp
> nil
> #+END_SRC
>
> #+RESULTS:
>
>
> I don't see why 'nil' is special than other values like 't'.

It is special because it is also how code evaluation specifies that
there is no produced output.

You may want to use :results scalar, e.g.,

  #+BEGIN_SRC emacs-lisp :results scalar
  nil
  #+END_SRC

  #+RESULTS:
  : nil

Regards,

-- 
Nicolas Goaziou