Re: Placement of list within an interactive clause

[carlmarcos--- via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

Jul 14, 2022, 21:12 by monnier@iro.umontreal.ca:

> carlmarcos@tutanota.com [2022-07-14 22:52:43] wrote:
>
>> My question was about how I can determine which parts are used to fill
>> elements to the list.  Whether it is from the body of `if' and `let'
>> clauses.  Perhaps I was not so articulate in the choice of words.
>>
>
> And my answer is that the expression returns a list and the origin of
> each part of the list is determined by the general semantics of Emacs
> Lisp (which is basically the same as that of all other programming
> languages in this respect).
>
>  Stefan
>
I have been reading as instructed.  

In summary. `(let` is a special function form. And a function in lisp returns the value of the last expression evaluated as the  return value.

Consequently, the following function will only take the last expression in the `let' body (completing-read) to fill an element of a list for setting the function argument `type'.

(defun myfun (type)
(interactive
(list
  (let ( (rqmatch t) (initpk "mixed") (dflt "extended")
(cseq '("expression" "mixed")) )
    (message "This is a message")
    (completing-read "Flare_type: " cseq nil rqmatch initpk nil dflt)))))

On the other hand if I want to have multiple function arguments, I should have

(defun myfun (type other-arg)
  (interactive
   (let ( (rqmatch t) (initpk "mixed") (dflt "extended")
  (cseq '("expression" "mixed")) )
     (message "This is a message")

     (list
      (completing-read "Flare_type: " cseq nil
       rqmatch initpk nil dflt)
      (completing-read "Other_arg: " cseq nil
       rqmatch initpk nil dflt)))))