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From: Jean Louis <bugs@gnu.support>
To: Dr Rainer Woitok <rainer.woitok@gmail.com>
Cc: Help-Gnu-Emacs@Gnu.Org
Subject: Re: (interactive) and &optional
Date: Fri, 24 Mar 2023 12:23:29 +0300	[thread overview]
Message-ID: <ZB1sEYG/tAnPVnwK@protected.localdomain> (raw)
In-Reply-To: <25628.42021.832534.376361@woitok.gmail.com>

* Dr Rainer Woitok <rainer.woitok@gmail.com> [2023-03-23 22:12]:
> Am I really expected in a function that is both,  callable from Lisp and
> via "M-x", to code something along the lines of
> 
>    (cond ((or (null arg) (string-empty-p arg)) 'default-val)
>          (arg))
> 
> to check whether or not an optional argument has been passed?  Are there
> any more elegant ways to achieve this?

I do not like involving `interactive' at all, so I do the handling by
providing optional argument and telling function to check for it, or
ask for it.

(defun search-something (&optional query)
  "Search something by using QUERY."
  (interactive)
  (let* ((query (or query (read-from-minibuffer "Query: "))))
    (do-the-search query)))

-- 
Jean

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  parent reply	other threads:[~2023-03-24  9:23 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-23 19:10 (interactive) and &optional Dr Rainer Woitok
2023-03-23 19:20 ` Philip Kaludercic
2023-03-25 12:35   ` Dr Rainer Woitok
2023-03-25 13:12     ` Philip Kaludercic
2023-03-25 14:33       ` [External] : " Drew Adams
2023-03-25 15:36         ` Dr Rainer Woitok
2023-03-25 16:58         ` Philip Kaludercic
2023-03-23 20:01 ` Emanuel Berg
2023-03-24  9:23 ` Jean Louis [this message]
2023-03-24 20:52   ` Philip Kaludercic
2023-03-24 21:07     ` Emanuel Berg
2023-03-27  1:52       ` [External] : " Drew Adams
2023-03-27  2:40         ` John Yates
2023-03-24 21:42     ` Jean Louis
2023-03-26  1:04       ` Emanuel Berg
2023-03-30 19:04         ` Jean Louis
2023-03-25 12:05   ` Dr Rainer Woitok
2023-03-25 14:32     ` Jean Louis
2023-03-25 15:41       ` Dr Rainer Woitok

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