Function: fill-individual-paragraphs

fill-individual-paragraphs is an interactive and byte-compiled function defined in fill.el.gz.

Signature

(fill-individual-paragraphs MIN MAX &optional JUSTIFY CITATION-REGEXP)

Documentation

Fill paragraphs of uniform indentation within the region.

This command divides the region into "paragraphs", treating every change in indentation level or prefix as a paragraph boundary, then fills each paragraph using its indentation level as the fill prefix.

There is one special case where a change in indentation does not start a new paragraph. This is for text of this form:

   foo> This line with extra indentation starts
   foo> a paragraph that continues on more lines.

These lines are filled together.

When calling from a program, pass the range to fill as the first two arguments.

Optional third and fourth arguments JUSTIFY and CITATION-REGEXP: JUSTIFY to justify paragraphs (prefix arg). When filling a mail message, pass a regexp for CITATION-REGEXP which will match the prefix of a line which is a citation marker plus whitespace, but no other kind of prefix. Also, if CITATION-REGEXP is non-nil, don't fill header lines.

View in manual

Probably introduced at or before Emacs version 19.1.

Key Bindings

Source Code

;; Defined in /usr/src/emacs/lisp/textmodes/fill.el.gz
(defun fill-individual-paragraphs (min max &optional justify citation-regexp)
  "Fill paragraphs of uniform indentation within the region.
This command divides the region into \"paragraphs\",
treating every change in indentation level or prefix as a paragraph boundary,
then fills each paragraph using its indentation level as the fill prefix.

There is one special case where a change in indentation does not start
a new paragraph.  This is for text of this form:

   foo>    This line with extra indentation starts
   foo> a paragraph that continues on more lines.

These lines are filled together.

When calling from a program, pass the range to fill
as the first two arguments.

Optional third and fourth arguments JUSTIFY and CITATION-REGEXP:
JUSTIFY to justify paragraphs (prefix arg).
When filling a mail message, pass a regexp for CITATION-REGEXP
which will match the prefix of a line which is a citation marker
plus whitespace, but no other kind of prefix.
Also, if CITATION-REGEXP is non-nil, don't fill header lines."
  (interactive (progn
		 (barf-if-buffer-read-only)
		 (list (region-beginning) (region-end)
		       (if current-prefix-arg 'full))))
  (save-restriction
    (save-excursion
      (goto-char min)
      (beginning-of-line)
      (narrow-to-region (point) max)
      (if citation-regexp
	  (while (and (not (eobp))
		      (or (looking-at "[ \t]*[^ \t\n]+:")
			  (looking-at "[ \t]*$")))
	    (if (looking-at "[ \t]*[^ \t\n]+:")
		(search-forward "\n\n" nil 'move)
	      (forward-line 1))))
      (narrow-to-region (point) max)
      ;; Loop over paragraphs.
      (while (progn
	       ;; Skip over all paragraph-separating lines
	       ;; so as to not include them in any paragraph.
               (while (and (not (eobp))
			   (progn (move-to-left-margin)
				  (and (not (eobp))
				       (looking-at paragraph-separate))))
                 (forward-line 1))
               (skip-chars-forward " \t\n") (not (eobp)))
	(move-to-left-margin)
	(let ((start (point))
	      fill-prefix fill-prefix-regexp)
	  ;; Find end of paragraph, and compute the smallest fill-prefix
	  ;; that fits all the lines in this paragraph.
	  (while (progn
		   ;; Update the fill-prefix on the first line
		   ;; and whenever the prefix good so far is too long.
		   (if (not (and fill-prefix
				 (looking-at fill-prefix-regexp)))
		       (setq fill-prefix
			     (fill-individual-paragraphs-prefix
			      citation-regexp)
			     fill-prefix-regexp (regexp-quote fill-prefix)))
		   (forward-line 1)
		   (if (bolp)
		       ;; If forward-line went past a newline,
		       ;; move further to the left margin.
		       (move-to-left-margin))
		   ;; Now stop the loop if end of paragraph.
		   (and (not (eobp))
			(if fill-individual-varying-indent
			    ;; If this line is a separator line, with or
			    ;; without prefix, end the paragraph.
			    (and
			     (not (looking-at paragraph-separate))
			     (save-excursion
			       (not (and (looking-at fill-prefix-regexp)
					 (progn (forward-char
						 (length fill-prefix))
						(looking-at
						 paragraph-separate))))))
			  ;; If this line has more or less indent
			  ;; than the fill prefix wants, end the paragraph.
			  (and (looking-at fill-prefix-regexp)
			       ;; If fill prefix is shorter than a new
			       ;; fill prefix computed here, end paragraph.
                               (let ((this-line-fill-prefix
				      (fill-individual-paragraphs-prefix
				       citation-regexp)))
                                 (>= (length fill-prefix)
                                     (length this-line-fill-prefix)))
			       (save-excursion
				 (not (progn (forward-char
					      (length fill-prefix))
					     (or (looking-at "[ \t]")
						 (looking-at paragraph-separate)
						 (looking-at paragraph-start)))))
			       (not (and (equal fill-prefix "")
					 citation-regexp
					 (looking-at citation-regexp))))))))
	  ;; Fill this paragraph, but don't add a newline at the end.
	  (let ((had-newline (bolp)))
	    (fill-region-as-paragraph start (point) justify)
	    (if (and (bolp) (not had-newline))
		(delete-char -1))))))))