(eval-when-compile (require 'cl))
(defcustom fill-flowed-display-column 'fill-column
"Column beyond which format=flowed lines are wrapped, when displayed.
This can be a Lisp expression or an integer."
:version "22.1"
:group 'mime-display
:type '(choice (const :tag "Standard `fill-column'" fill-column)
(const :tag "Fit Window" (- (window-width) 5))
(sexp)
(integer)))
(defcustom fill-flowed-encode-column 66
"Column beyond which format=flowed lines are wrapped, in outgoing messages.
This can be a Lisp expression or an integer.
RFC 2646 suggests 66 characters for readability."
:version "22.1"
:group 'mime-display
:type '(choice (const :tag "Standard fill-column" fill-column)
(const :tag "RFC 2646 default (66)" 66)
(sexp)
(integer)))
(eval-and-compile
(defalias 'fill-flowed-point-at-bol
(if (fboundp 'point-at-bol)
'point-at-bol
'line-beginning-position))
(defalias 'fill-flowed-point-at-eol
(if (fboundp 'point-at-eol)
'point-at-eol
'line-end-position)))
(defun fill-flowed-encode (&optional buffer)
(with-current-buffer (or buffer (current-buffer))
(when use-hard-newlines
(let ((start (point-min)) end)
(while (setq end (text-property-any start (point-max) 'hard 't))
(let ((fill-column (eval fill-flowed-encode-column)))
(fill-region start end t 'nosqueeze 'to-eop))
(goto-char start)
(setq end (text-property-any start (point-max) 'hard 't))
(while (and (< (point) end)
(re-search-forward "$" (1- end) t))
(insert " ")
(setq end (1+ end))
(forward-char))
(goto-char (setq start (1+ end)))))
t)))
(defun fill-flowed (&optional buffer)
(save-excursion
(set-buffer (or (current-buffer) buffer))
(goto-char (point-min))
(while (re-search-forward "^\\( \\|>+ $\\)" nil t)
(delete-char -1)
(forward-line 1))
(goto-char (point-min))
(while (re-search-forward " $" nil t)
(when (save-excursion
(beginning-of-line)
(looking-at "^\\(>*\\)\\( ?\\)"))
(let ((quote (match-string 1))
sig)
(if (string= quote "")
(setq quote nil))
(when (and quote (string= (match-string 2) ""))
(save-excursion
(beginning-of-line)
(when (> (skip-chars-forward ">") 0)
(insert " "))))
(while (and (save-excursion
(ignore-errors (backward-char 3))
(setq sig (looking-at "-- "))
(looking-at "[^-][^-] "))
(save-excursion
(unless (eobp)
(forward-char 1)
(looking-at (format "^\\(%s\\)\\([^>\n\r]\\)"
(or quote " ?"))))))
(save-excursion
(replace-match (if (string= (match-string 2) " ")
"" "\\2")))
(backward-delete-char -1)
(end-of-line))
(unless sig
(condition-case nil
(let ((fill-prefix (when quote (concat quote " ")))
(fill-column (eval fill-flowed-display-column))
filladapt-mode
adaptive-fill-mode)
(fill-region (fill-flowed-point-at-bol)
(min (1+ (fill-flowed-point-at-eol))
(point-max))
'left 'nosqueeze))
(error
(forward-line 1)
nil))))))))
(eval-when-compile
(defvar show-trailing-whitespace))
(defvar fill-flowed-encode-tests
`(
(,(concat
"> Thou villainous ill-breeding spongy dizzy-eyed \n"
"> reeky elf-skinned pigeon-egg! \n"
">> Thou artless swag-bellied milk-livered \n"
">> dismal-dreaming idle-headed scut!\n"
">>> Thou errant folly-fallen spleeny reeling-ripe \n"
">>> unmuzzled ratsbane!\n"
">>>> Henceforth, the coding style is to be strictly \n"
">>>> enforced, including the use of only upper case.\n"
">>>>> I've noticed a lack of adherence to the coding \n"
">>>>> styles, of late.\n"
">>>>>> Any complaints?")
.
,(concat
"> Thou villainous ill-breeding spongy dizzy-eyed reeky elf-skinned\n"
"> pigeon-egg! \n"
">> Thou artless swag-bellied milk-livered dismal-dreaming idle-headed\n"
">> scut!\n"
">>> Thou errant folly-fallen spleeny reeling-ripe unmuzzled ratsbane!\n"
">>>> Henceforth, the coding style is to be strictly enforced,\n"
">>>> including the use of only upper case.\n"
">>>>> I've noticed a lack of adherence to the coding styles, of late.\n"
">>>>>> Any complaints?\n"
))
))
(defun fill-flowed-test ()
(interactive "")
(switch-to-buffer (get-buffer-create "*Format=Flowed test output*"))
(erase-buffer)
(setq show-trailing-whitespace t)
(dolist (test fill-flowed-encode-tests)
(let (start output)
(insert "***** BEGIN TEST INPUT *****\n")
(insert (car test))
(insert "***** END TEST INPUT *****\n\n")
(insert "***** BEGIN TEST OUTPUT *****\n")
(setq start (point))
(insert (car test))
(save-restriction
(narrow-to-region start (point))
(fill-flowed))
(setq output (buffer-substring start (point-max)))
(insert "***** END TEST OUTPUT *****\n")
(unless (string= output (cdr test))
(insert "\n***** BEGIN TEST EXPECTED OUTPUT *****\n")
(insert (cdr test))
(insert "***** END TEST EXPECTED OUTPUT *****\n"))
(insert "\n\n")))
(goto-char (point-max)))
(provide 'flow-fill)