Re: [External] : Find the longest word in the word list file.

[Hongyi Zhao]

On Wed, Aug 11, 2021 at 9:51 AM Drew Adams <drew.adams@oracle.com> wrote:
>
> > I have an English word list file that stores words in a
> > one-word-per-line format. Now I want to find the longest word in the
> > word list file. For example, I can use standard UNIX tools to
> > accomplish this with the following simple commands:
> >
> > $ awk '$0 ~ /^[[:alpha:]]+$/ { print $0, length($0) }'
> > american-english-exhaustive | \
> > sort -k2n | tail -1
> > Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch 58
> >
> > But in Emacs, what is the elisp implementation for the above task?
>
> I use this, from `misc-cmds.el' 
> (https://www.emacswiki.org/emacs/download/misc-cmds.el).
>
> I bind it to `C-<end>' in `isearch-mode-map'.  It takes you to the longest 
> line after the cursor (repeatable).  Since you have one word per line it 
> should do what you want.  Of course if you just want a code snippet you can 
> dig that out of it also.
>
> (defun goto-longest-line (beg end &optional msgp)
>   "Go to the first of the longest lines in the region or buffer.
> If the region is active, it is checked.
> If not, the buffer (or its restriction) is checked.
>
> Returns a list of three elements:
>
>  (LINE LINE-LENGTH OTHER-LINES LINES-CHECKED)
>
> LINE is the first of the longest lines measured.
> LINE-LENGTH is the length of LINE.
> OTHER-LINES is a list of other lines checked that are as long as LINE.
> LINES-CHECKED is the number of lines measured.
>
> Interactively, a message displays this information.
>
> If there is only one line in the active region, then the region is
> deactivated after this command, and the message mentions only LINE and
> LINE-LENGTH.
>
> If this command is repeated, it checks for the longest line after the
> cursor.  That is *not* necessarily the longest line other than the
> current line.  That longest line could be before or after the current
> line.
>
> To search only from the current line forward, not throughout the
> buffer, you can use `C-SPC' to set the mark, then use this
> \(repeatedly)."
>   (interactive
>    (if (or (not mark-active)  (not (< (region-beginning) (region-end))))
>        (list (point-min) (point-max))
>      (if (< (point) (mark))
>          (list (point) (mark) 'MSGP)
>        (list (mark) (point) 'MSGP))))
>   (when (and (not mark-active)  (= beg end)) (error "The buffer is empty"))
>   (when (and mark-active  (> (point) (mark))) (exchange-point-and-mark))
>   (when (< end beg) (setq end  (prog1 beg (setq beg  end))))
>   (when (eq 'goto-longest-line last-command)
>     (forward-line 1) (setq beg  (point)))
>   (goto-char beg)
>   (when (eobp) (error "End of buffer"))
>   (cond ((<= end (save-excursion (goto-char beg) (forward-line 1) (point)))
>          (let ((inhibit-field-text-motion  t))  (beginning-of-line))
>          (when (and (> emacs-major-version 21)  (require 'hl-line nil t))
>            (let ((hl-line-mode  t))  (hl-line-highlight))
>            (add-hook 'pre-command-hook #'hl-line-unhighlight nil t))
>          (let ((lineno  (line-number-at-pos))
>                (chars   (let ((inhibit-field-text-motion  t))
>                           (save-excursion (end-of-line) (current-column)))))
>            (message "Only line %d: %d chars" lineno chars)
>            (let ((visible-bell  t))  (ding))
>            (setq mark-active  nil)
>            (list lineno chars nil 1)))
>         (t
>          (let* ((start-line                 (line-number-at-pos))
>                 (max-width                  0)
>                 (line                       start-line)
>                 (inhibit-field-text-motion  t)
>                 long-lines col)
>            (when (eobp) (error "End of buffer"))
>            (while (and (not (eobp))  (< (point) end))
>              (end-of-line)
>              (setq col  (current-column))
>              (when (>= col max-width)
>                (setq long-lines  (if (= col max-width)
>                                      (cons line long-lines)
>                                    (list line))
>                      max-width   col))
>              (forward-line 1)
>              (setq line  (1+ line)))
>            (setq long-lines  (nreverse long-lines))
>            (let ((lines  long-lines))
>              (while (and lines  (> start-line (car lines))) (pop lines))
>              (goto-char (point-min))
>              (when (car lines) (forward-line (1- (car lines)))))
>            (when (and (> emacs-major-version 21)  (require 'hl-line nil t))
>              (let ((hl-line-mode  t))  (hl-line-highlight))
>              (add-hook 'pre-command-hook #'hl-line-unhighlight nil t))
>            (when msgp
>              (let ((others  (cdr long-lines)))
>                (message "Line %d: %d chars%s (%d lines measured)"
>                         (car long-lines) max-width
>                         (concat
>                          (and others
>                               (format ", Others: {%s}" (mapconcat
>                                                         (lambda (line) 
> (format "%d" line))
>                                                         (cdr long-lines) ", 
> "))))
>                         (- line start-line))))
>            (list (car long-lines) max-width (cdr long-lines) (- line 
> start-line))))))

Thank you for your solution, but it seems so complicated to me.

Best regards
-- 
Assoc. Prof. Hongyi Zhao <hongyi.zhao@gmail.com>
Theory and Simulation of Materials
Hebei Vocational University of Technology and Engineering
No. 473, Quannan West Street, Xindu District, Xingtai, Hebei province