bug#50726: 26.3; Let `count-words(-region)' count only words entirely within the region

[Stefan Kangas <stefan@marxist.se>]

Drew Adams <drew.adams@oracle.com> writes:

> Enhancement request.
>
> A word that straddles the beginning or end of the region is counted as a
> word in the region.  It would be good to be able to have such functions
> not count such partial words.
> ___
>
> Here's an example of a command that counts the words in a rectangular
> region.  By default it excludes words that straddle the row boundaries,
> but a prefix arg counts such partial words also.
>
> https://emacs.stackexchange.com/a/68611/105

Copying in the code below.  I have no comment, besides to say that a
more strict `count-words' could perhaps be named `count-words-strict'.

(defun count-words-rectangle (start end &optional allow-partial-p msgp)
  "Count words in the rectangle from START to END.
This is similar to `count-words', but for a rectangular region.

Also:

* By default, a word that straddles the beginning or end of a
  rectangle row is not counted.  That is, this counts only words that
  are entirely within the rectangle.
* A prefix arg means count also such partial words at row boundaries.

If called interactively, START and END are the bounds of the start and
end of the active region.  Print a message reporting the number of
rows (lines), columns (characters per row), words, and characters.

If called from Lisp, return the number of words in the rectangle
between START and END, without printing any message."
  (interactive "r\nP\np")
  (let ((bounds  (extract-rectangle-bounds start end))
        (words   0)
        (chars   0))
    (dolist (beg+end  bounds)
      (setq words  (+ words (count-words (car beg+end) (cdr beg+end)))))
    (let (beg end)
      (dolist (beg+end  bounds)
        (setq beg  (car beg+end)
              end  (cdr beg+end))
        (unless allow-partial-p
          (when (and (char-after (1- beg))  (equal '(2) (syntax-after (1- beg)))
                     (char-after beg)       (equal '(2) (syntax-after beg)))
            (setq words  (1- words)))
          (when (and (char-after (1- end))  (equal '(2) (syntax-after (1- end)))
                     (char-after end)       (equal '(2) (syntax-after     end)))
            (setq words  (1- words))))))
    (when msgp
      (dolist
          (beg+end  bounds)
        (setq chars  (+ chars (- (cdr beg+end) (car beg+end)))))
      (let ((rows  (count-lines start end))
            (cols  (let ((rpc  (save-excursion
                                 (rectangle--pos-cols
(region-beginning) (region-end)))))
                     (abs (- (car rpc) (cdr rpc))))))
        (message "Rectangle has %d row%s, %d colum%s, %d word%s, and %d char%s."
                 rows  (if (= rows 1)  "" "s")
                 cols  (if (= cols 1)  "" "s")
                 words (if (= words 1) "" "s")
                 chars (if (= chars 1) "" "s"))))
    words))