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From: Eli Zaretskii <eliz@gnu.org>
Newsgroups: gmane.emacs.help
Subject: Re: Inserting some text in a working buffer
Date: Sun, 09 May 2021 10:12:31 +0300
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In-Reply-To: <874kfcv95i.fsf@zoho.eu> (message from Emanuel Berg via Users
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> Date: Sun, 09 May 2021 06:11:21 +0200
> From:  Emanuel Berg via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>
> 
> (defun insert-char-to-col (char col)
>   "Insert CHAR to COL."
>   (interactive "cchar: \nncol: ")
>   (let*((len (- col (current-column)))
>         (str (make-string len char)) )
>     (insert str) ))

This seems to assume that each character takes just one column.  But
some characters, called "double-width characters", take 2 columns, not
1.  So using make-string here is not TRT, because its LENGTH argument
counts characters, not columns.