-;;; cal-islam.el --- calendar functions for the Islamic calendar
-
-;; Copyright (C) 1995, 1997, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
-;; 2008 Free Software Foundation, Inc.
-
-;; Author: Edward M. Reingold <reingold@cs.uiuc.edu>
-;; Maintainer: Glenn Morris <rgm@gnu.org>
-;; Keywords: calendar
-;; Human-Keywords: Islamic calendar, calendar, diary
-
-;; This file is part of GNU Emacs.
-
-;; GNU Emacs is free software; you can redistribute it and/or modify
-;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation; either version 3, or (at your option)
-;; any later version.
-
-;; GNU Emacs is distributed in the hope that it will be useful,
-;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-;; GNU General Public License for more details.
-
-;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
-;; Boston, MA 02110-1301, USA.
-
-;;; Commentary:
-
-;; This collection of functions implements the features of calendar.el and
-;; diary.el that deal with the Islamic calendar.
-
-;; Technical details of all the calendrical calculations can be found in
-;; ``Calendrical Calculations: The Millennium Edition'' by Edward M. Reingold
-;; and Nachum Dershowitz, Cambridge University Press (2001).
-
-;;; Code:
-
-(defvar date)
-(defvar displayed-month)
-(defvar displayed-year)
-(defvar number)
-(defvar original-date)
-
-(require 'cal-julian)
-
-(defvar calendar-islamic-month-name-array
- ["Muharram" "Safar" "Rabi I" "Rabi II" "Jumada I" "Jumada II"
- "Rajab" "Sha'ban" "Ramadan" "Shawwal" "Dhu al-Qada" "Dhu al-Hijjah"]
-"Array of strings giving the names of the Islamic months.")
-
-(defvar calendar-islamic-epoch (calendar-absolute-from-julian '(7 16 622))
- "Absolute date of start of Islamic calendar = August 29, 284 A.D. (Julian).")
-
-(defun islamic-calendar-leap-year-p (year)
- "Returns t if YEAR is a leap year on the Islamic calendar."
- (memq (% year 30)
- (list 2 5 7 10 13 16 18 21 24 26 29)))
-
-(defun islamic-calendar-last-day-of-month (month year)
- "The last day in MONTH during YEAR on the Islamic calendar."
- (cond
- ((memq month (list 1 3 5 7 9 11)) 30)
- ((memq month (list 2 4 6 8 10)) 29)
- (t (if (islamic-calendar-leap-year-p year) 30 29))))
-
-(defun islamic-calendar-day-number (date)
- "Return the day number within the year of the Islamic date DATE."
- (let* ((month (extract-calendar-month date))
- (day (extract-calendar-day date)))
- (+ (* 30 (/ month 2))
- (* 29 (/ (1- month) 2))
- day)))
-
-(defun calendar-absolute-from-islamic (date)
- "Absolute date of Islamic DATE.
-The absolute date is the number of days elapsed since the (imaginary)
-Gregorian date Sunday, December 31, 1 BC."
- (let* ((month (extract-calendar-month date))
- (day (extract-calendar-day date))
- (year (extract-calendar-year date))
- (y (% year 30))
- (leap-years-in-cycle
- (cond
- ((< y 3) 0) ((< y 6) 1) ((< y 8) 2) ((< y 11) 3) ((< y 14) 4)
- ((< y 17) 5) ((< y 19) 6) ((< y 22) 7) ((< y 25) 8) ((< y 27) 9)
- (t 10))))
- (+ (islamic-calendar-day-number date);; days so far this year
- (* (1- year) 354) ;; days in all non-leap years
- (* 11 (/ year 30)) ;; leap days in complete cycles
- leap-years-in-cycle ;; leap days this cycle
- (1- calendar-islamic-epoch)))) ;; days before start of calendar
-
-(defun calendar-islamic-from-absolute (date)
- "Compute the Islamic date (month day year) corresponding to absolute DATE.
-The absolute date is the number of days elapsed since the (imaginary)
-Gregorian date Sunday, December 31, 1 BC."
- (if (< date calendar-islamic-epoch)
- (list 0 0 0);; pre-Islamic date
- (let* ((approx (/ (- date calendar-islamic-epoch)
- 355));; Approximation from below.
- (year ;; Search forward from the approximation.
- (+ approx
- (calendar-sum y approx
- (>= date (calendar-absolute-from-islamic
- (list 1 1 (1+ y))))
- 1)))
- (month ;; Search forward from Muharram.
- (1+ (calendar-sum m 1
- (> date
- (calendar-absolute-from-islamic
- (list m
- (islamic-calendar-last-day-of-month
- m year)
- year)))
- 1)))
- (day ;; Calculate the day by subtraction.
- (- date
- (1- (calendar-absolute-from-islamic (list month 1 year))))))
- (list month day year))))
-
-;;;###autoload
-(defun calendar-islamic-date-string (&optional date)
- "String of Islamic date before sunset of Gregorian DATE.
-Returns the empty string if DATE is pre-Islamic.
-Defaults to today's date if DATE is not given.
-Driven by the variable `calendar-date-display-form'."
- (let ((calendar-month-name-array calendar-islamic-month-name-array)
- (islamic-date (calendar-islamic-from-absolute
- (calendar-absolute-from-gregorian
- (or date (calendar-current-date))))))
- (if (< (extract-calendar-year islamic-date) 1)
- ""
- (calendar-date-string islamic-date nil t))))
-
-;;;###autoload
-(defun calendar-print-islamic-date ()
- "Show the Islamic calendar equivalent of the date under the cursor."
- (interactive)
- (let ((i (calendar-islamic-date-string (calendar-cursor-to-date t))))
- (if (string-equal i "")
- (message "Date is pre-Islamic")
- (message "Islamic date (until sunset): %s" i))))
-
-;;;###autoload
-(defun calendar-goto-islamic-date (date &optional noecho)
- "Move cursor to Islamic DATE; echo Islamic date unless NOECHO is t."
- (interactive
- (let* ((today (calendar-current-date))
- (year (calendar-read
- "Islamic calendar year (>0): "
- (lambda (x) (> x 0))
- (int-to-string
- (extract-calendar-year
- (calendar-islamic-from-absolute
- (calendar-absolute-from-gregorian today))))))
- (month-array calendar-islamic-month-name-array)
- (completion-ignore-case t)
- (month (cdr (assoc-string
- (completing-read
- "Islamic calendar month name: "
- (mapcar 'list (append month-array nil))
- nil t)
- (calendar-make-alist month-array 1) t)))
- (last (islamic-calendar-last-day-of-month month year))
- (day (calendar-read
- (format "Islamic calendar day (1-%d): " last)
- (lambda (x) (and (< 0 x) (<= x last))))))
- (list (list month day year))))
- (calendar-goto-date (calendar-gregorian-from-absolute
- (calendar-absolute-from-islamic date)))
- (or noecho (calendar-print-islamic-date)))
-
-(defun diary-islamic-date ()
- "Islamic calendar equivalent of date diary entry."
- (let ((i (calendar-islamic-date-string date)))
- (if (string-equal i "")
- "Date is pre-Islamic"
- (format "Islamic date (until sunset): %s" i))))
-
-(defun holiday-islamic (month day string)
- "Holiday on MONTH, DAY (Islamic) called STRING.
-If MONTH, DAY (Islamic) is visible, the value returned is corresponding
-Gregorian date in the form of the list (((month day year) STRING)). Returns
-nil if it is not visible in the current calendar window."
- (let* ((islamic-date (calendar-islamic-from-absolute
- (calendar-absolute-from-gregorian
- (list displayed-month 15 displayed-year))))
- (m (extract-calendar-month islamic-date))
- (y (extract-calendar-year islamic-date))
- (date))
- (if (< m 1)
- nil;; Islamic calendar doesn't apply.
- (increment-calendar-month m y (- 10 month))
- (if (> m 7);; Islamic date might be visible
- (let ((date (calendar-gregorian-from-absolute
- (calendar-absolute-from-islamic (list month day y)))))
- (if (calendar-date-is-visible-p date)
- (list (list date string))))))))
-
-;; l-i-d-e should be called from diary code.
-(declare-function add-to-diary-list "diary-lib"
- (date string specifier &optional marker globcolor literal))
-
-(defun list-islamic-diary-entries ()
- "Add any Islamic date entries from the diary file to `diary-entries-list'.
-Islamic date diary entries must be prefaced by an `islamic-diary-entry-symbol'
-\(normally an `I'). The same diary date forms govern the style of the Islamic
-calendar entries, except that the Islamic month names must be spelled in full.
-The Islamic months are numbered from 1 to 12 with Muharram being 1 and 12 being
-Dhu al-Hijjah. If an Islamic date diary entry begins with a
-`diary-nonmarking-symbol', the entry will appear in the diary listing, but will
-not be marked in the calendar. This function is provided for use with the
-`nongregorian-diary-listing-hook'."
- (if (< 0 number)
- (let ((buffer-read-only nil)
- (diary-modified (buffer-modified-p))
- (gdate original-date)
- (mark (regexp-quote diary-nonmarking-symbol)))
- (dotimes (idummy number)
- (let* ((d diary-date-forms)
- (idate (calendar-islamic-from-absolute
- (calendar-absolute-from-gregorian gdate)))
- (month (extract-calendar-month idate))
- (day (extract-calendar-day idate))
- (year (extract-calendar-year idate)))
- (while d
- (let*
- ((date-form (if (equal (car (car d)) 'backup)
- (cdr (car d))
- (car d)))
- (backup (equal (car (car d)) 'backup))
- (dayname
- (format "%s\\|%s\\.?"
- (calendar-day-name gdate)
- (calendar-day-name gdate 'abbrev)))
- (calendar-month-name-array
- calendar-islamic-month-name-array)
- (monthname
- (concat
- "\\*\\|"
- (calendar-month-name month)))
- (month (concat "\\*\\|0*" (int-to-string month)))
- (day (concat "\\*\\|0*" (int-to-string day)))
- (year
- (concat
- "\\*\\|0*" (int-to-string year)
- (if abbreviated-calendar-year
- (concat "\\|" (int-to-string (% year 100)))
- "")))
- (regexp
- (concat
- "\\(\\`\\|\^M\\|\n\\)" mark "?"
- (regexp-quote islamic-diary-entry-symbol)
- "\\("
- (mapconcat 'eval date-form "\\)\\(")
- "\\)"))
- (case-fold-search t))
- (goto-char (point-min))
- (while (re-search-forward regexp nil t)
- (if backup (re-search-backward "\\<" nil t))
- (if (and (or (char-equal (preceding-char) ?\^M)
- (char-equal (preceding-char) ?\n))
- (not (looking-at " \\|\^I")))
- ;; Diary entry that consists only of date.
- (backward-char 1)
- ;; Found a nonempty diary entry--make it visible and
- ;; add it to the list.
- (let ((entry-start (point))
- (date-start))
- (re-search-backward "\^M\\|\n\\|\\`")
- (setq date-start (point))
- (re-search-forward "\^M\\|\n" nil t 2)
- (while (looking-at " \\|\^I")
- (re-search-forward "\^M\\|\n" nil t))
- (backward-char 1)
- (subst-char-in-region date-start (point) ?\^M ?\n t)
- (add-to-diary-list
- gdate
- (buffer-substring-no-properties entry-start (point))
- (buffer-substring-no-properties
- (1+ date-start) (1- entry-start))
- (copy-marker entry-start))))))
- (setq d (cdr d))))
- (setq gdate
- (calendar-gregorian-from-absolute
- (1+ (calendar-absolute-from-gregorian gdate)))))
- (set-buffer-modified-p diary-modified))
- (goto-char (point-min))))
-
-(declare-function diary-name-pattern "diary-lib"
- (string-array &optional abbrev-array paren))
-
-(declare-function mark-calendar-days-named "diary-lib"
- (dayname &optional color))
-
-(defun mark-islamic-diary-entries ()
- "Mark days in the calendar window that have Islamic date diary entries.
-Each entry in diary-file (or included files) visible in the calendar window
-is marked. Islamic date entries are prefaced by a islamic-diary-entry-symbol
-\(normally an `I'). The same diary-date-forms govern the style of the Islamic
-calendar entries, except that the Islamic month names must be spelled in full.
-The Islamic months are numbered from 1 to 12 with Muharram being 1 and 12 being
-Dhu al-Hijjah. Islamic date diary entries that begin with a
-diary-nonmarking-symbol will not be marked in the calendar. This function is
-provided for use as part of the nongregorian-diary-marking-hook."
- (let ((d diary-date-forms))
- (while d
- (let*
- ((date-form (if (equal (car (car d)) 'backup)
- (cdr (car d))
- (car d)));; ignore 'backup directive
- (dayname (diary-name-pattern calendar-day-name-array
- calendar-day-abbrev-array))
- (monthname
- (format "%s\\|\\*"
- (diary-name-pattern calendar-islamic-month-name-array)))
- (month "[0-9]+\\|\\*")
- (day "[0-9]+\\|\\*")
- (year "[0-9]+\\|\\*")
- (l (length date-form))
- (d-name-pos (- l (length (memq 'dayname date-form))))
- (d-name-pos (if (/= l d-name-pos) (+ 2 d-name-pos)))
- (m-name-pos (- l (length (memq 'monthname date-form))))
- (m-name-pos (if (/= l m-name-pos) (+ 2 m-name-pos)))
- (d-pos (- l (length (memq 'day date-form))))
- (d-pos (if (/= l d-pos) (+ 2 d-pos)))
- (m-pos (- l (length (memq 'month date-form))))
- (m-pos (if (/= l m-pos) (+ 2 m-pos)))
- (y-pos (- l (length (memq 'year date-form))))
- (y-pos (if (/= l y-pos) (+ 2 y-pos)))
- (regexp
- (concat
- "\\(\\`\\|\^M\\|\n\\)"
- (regexp-quote islamic-diary-entry-symbol)
- "\\("
- (mapconcat 'eval date-form "\\)\\(")
- "\\)"))
- (case-fold-search t))
- (goto-char (point-min))
- (while (re-search-forward regexp nil t)
- (let* ((dd-name
- (if d-name-pos
- (buffer-substring
- (match-beginning d-name-pos)
- (match-end d-name-pos))))
- (mm-name
- (if m-name-pos
- (buffer-substring
- (match-beginning m-name-pos)
- (match-end m-name-pos))))
- (mm (string-to-number
- (if m-pos
- (buffer-substring
- (match-beginning m-pos)
- (match-end m-pos))
- "")))
- (dd (string-to-number
- (if d-pos
- (buffer-substring
- (match-beginning d-pos)
- (match-end d-pos))
- "")))
- (y-str (if y-pos
- (buffer-substring
- (match-beginning y-pos)
- (match-end y-pos))))
- (yy (if (not y-str)
- 0
- (if (and (= (length y-str) 2)
- abbreviated-calendar-year)
- (let* ((current-y
- (extract-calendar-year
- (calendar-islamic-from-absolute
- (calendar-absolute-from-gregorian
- (calendar-current-date)))))
- (y (+ (string-to-number y-str)
- (* 100 (/ current-y 100)))))
- (if (> (- y current-y) 50)
- (- y 100)
- (if (> (- current-y y) 50)
- (+ y 100)
- y)))
- (string-to-number y-str)))))
- (if dd-name
- (mark-calendar-days-named
- (cdr (assoc-string dd-name
- (calendar-make-alist
- calendar-day-name-array
- 0 nil calendar-day-abbrev-array) t)))
- (if mm-name
- (setq mm (if (string-equal mm-name "*") 0
- (cdr (assoc-string
- mm-name
- (calendar-make-alist
- calendar-islamic-month-name-array) t)))))
- (mark-islamic-calendar-date-pattern mm dd yy)))))
- (setq d (cdr d)))))
-
-(defun mark-islamic-calendar-date-pattern (month day year)
- "Mark dates in calendar window that conform to Islamic date MONTH/DAY/YEAR.
-A value of 0 in any position is a wildcard."
- (save-excursion
- (set-buffer calendar-buffer)
- (if (and (not (zerop month)) (not (zerop day)))
- (if (not (zerop year))
- ;; Fully specified Islamic date.
- (let ((date (calendar-gregorian-from-absolute
- (calendar-absolute-from-islamic
- (list month day year)))))
- (if (calendar-date-is-visible-p date)
- (mark-visible-calendar-date date)))
- ;; Month and day in any year--this taken from the holiday stuff.
- (let* ((islamic-date (calendar-islamic-from-absolute
- (calendar-absolute-from-gregorian
- (list displayed-month 15 displayed-year))))
- (m (extract-calendar-month islamic-date))
- (y (extract-calendar-year islamic-date))
- (date))
- (if (< m 1)
- nil;; Islamic calendar doesn't apply.
- (increment-calendar-month m y (- 10 month))
- (if (> m 7);; Islamic date might be visible
- (let ((date (calendar-gregorian-from-absolute
- (calendar-absolute-from-islamic
- (list month day y)))))
- (if (calendar-date-is-visible-p date)
- (mark-visible-calendar-date date)))))))
- ;; Not one of the simple cases--check all visible dates for match.
- ;; Actually, the following code takes care of ALL of the cases, but
- ;; it's much too slow to be used for the simple (common) cases.
- (let ((m displayed-month)
- (y displayed-year)
- (first-date)
- (last-date))
- (increment-calendar-month m y -1)
- (setq first-date
- (calendar-absolute-from-gregorian
- (list m 1 y)))
- (increment-calendar-month m y 2)
- (setq last-date
- (calendar-absolute-from-gregorian
- (list m (calendar-last-day-of-month m y) y)))
- (calendar-for-loop date from first-date to last-date do
- (let* ((i-date (calendar-islamic-from-absolute date))
- (i-month (extract-calendar-month i-date))
- (i-day (extract-calendar-day i-date))
- (i-year (extract-calendar-year i-date)))
- (and (or (zerop month)
- (= month i-month))
- (or (zerop day)
- (= day i-day))
- (or (zerop year)
- (= year i-year))
- (mark-visible-calendar-date
- (calendar-gregorian-from-absolute date)))))))))
-
-;;;###autoload
-(defun insert-islamic-diary-entry (arg)
- "Insert a diary entry.
-For the Islamic date corresponding to the date indicated by point.
-Prefix arg will make the entry nonmarking."
- (interactive "P")
- (let* ((calendar-month-name-array calendar-islamic-month-name-array))
- (make-diary-entry
- (concat
- islamic-diary-entry-symbol
- (calendar-date-string
- (calendar-islamic-from-absolute
- (calendar-absolute-from-gregorian
- (calendar-cursor-to-date t)))
- nil t))
- arg)))
-
-;;;###autoload
-(defun insert-monthly-islamic-diary-entry (arg)
- "Insert a monthly diary entry.
-For the day of the Islamic month corresponding to the date indicated by point.
-Prefix arg will make the entry nonmarking."
- (interactive "P")
- (let* ((calendar-date-display-form
- (if european-calendar-style '(day " * ") '("* " day )))
- (calendar-month-name-array calendar-islamic-month-name-array))
- (make-diary-entry
- (concat
- islamic-diary-entry-symbol
- (calendar-date-string
- (calendar-islamic-from-absolute
- (calendar-absolute-from-gregorian
- (calendar-cursor-to-date t)))))
- arg)))
-
-;;;###autoload
-(defun insert-yearly-islamic-diary-entry (arg)
- "Insert an annual diary entry.
-For the day of the Islamic year corresponding to the date indicated by point.
-Prefix arg will make the entry nonmarking."
- (interactive "P")
- (let* ((calendar-date-display-form
- (if european-calendar-style
- '(day " " monthname)
- '(monthname " " day)))
- (calendar-month-name-array calendar-islamic-month-name-array))
- (make-diary-entry
- (concat
- islamic-diary-entry-symbol
- (calendar-date-string
- (calendar-islamic-from-absolute
- (calendar-absolute-from-gregorian
- (calendar-cursor-to-date t)))))
- arg)))
-
-(provide 'cal-islam)
-
-;; Local Variables:
-;; generated-autoload-file: "cal-loaddefs.el"
-;; End:
-
-;; arch-tag: a951b6c1-6f47-48d5-bac3-1b505cd719f7
-;;; cal-islam.el ends here
+;;; cal-islam.el --- calendar functions for the Islamic calendar
+
+;; Copyright (C) 1995, 1997, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
+;; 2008, 2009, 2010 Free Software Foundation, Inc.
+
+;; Author: Edward M. Reingold <reingold@cs.uiuc.edu>
+;; Maintainer: Glenn Morris <rgm@gnu.org>
+;; Keywords: calendar
+;; Human-Keywords: Islamic calendar, calendar, diary
+;; Package: calendar
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; See calendar.el.
+
+;;; Code:
+
+(require 'calendar)
+
+(defconst calendar-islamic-month-name-array
+ ["Muharram" "Safar" "Rabi I" "Rabi II" "Jumada I" "Jumada II"
+ "Rajab" "Sha'ban" "Ramadan" "Shawwal" "Dhu al-Qada" "Dhu al-Hijjah"]
+"Array of strings giving the names of the Islamic months.")
+
+(eval-and-compile
+ (autoload 'calendar-julian-to-absolute "cal-julian"))
+
+(defconst calendar-islamic-epoch
+ (eval-when-compile (calendar-julian-to-absolute '(7 16 622)))
+ "Absolute date of start of Islamic calendar = July 16, 622 AD (Julian).")
+
+(defun calendar-islamic-leap-year-p (year)
+ "Return t if YEAR is a leap year on the Islamic calendar."
+ (memq (% year 30)
+ (list 2 5 7 10 13 16 18 21 24 26 29)))
+
+(defun calendar-islamic-last-day-of-month (month year)
+ "The last day in MONTH during YEAR on the Islamic calendar."
+ (cond
+ ((memq month (list 1 3 5 7 9 11)) 30)
+ ((memq month (list 2 4 6 8 10)) 29)
+ (t (if (calendar-islamic-leap-year-p year) 30 29))))
+
+(defun calendar-islamic-day-number (date)
+ "Return the day number within the year of the Islamic date DATE."
+ (let ((month (calendar-extract-month date)))
+ (+ (* 30 (/ month 2))
+ (* 29 (/ (1- month) 2))
+ (calendar-extract-day date))))
+
+(defun calendar-islamic-to-absolute (date)
+ "Absolute date of Islamic DATE.
+The absolute date is the number of days elapsed since the (imaginary)
+Gregorian date Sunday, December 31, 1 BC."
+ (let* ((month (calendar-extract-month date))
+ (day (calendar-extract-day date))
+ (year (calendar-extract-year date))
+ (y (% year 30))
+ (leap-years-in-cycle (cond ((< y 3) 0)
+ ((< y 6) 1)
+ ((< y 8) 2)
+ ((< y 11) 3)
+ ((< y 14) 4)
+ ((< y 17) 5)
+ ((< y 19) 6)
+ ((< y 22) 7)
+ ((< y 25) 8)
+ ((< y 27) 9)
+ (t 10))))
+ (+ (calendar-islamic-day-number date) ; days so far this year
+ (* (1- year) 354) ; days in all non-leap years
+ (* 11 (/ year 30)) ; leap days in complete cycles
+ leap-years-in-cycle ; leap days this cycle
+ (1- calendar-islamic-epoch)))) ; days before start of calendar
+
+(define-obsolete-function-alias 'calendar-absolute-from-islamic
+ 'calendar-islamic-to-absolute "23.1")
+
+(defun calendar-islamic-from-absolute (date)
+ "Compute the Islamic date (month day year) corresponding to absolute DATE.
+The absolute date is the number of days elapsed since the (imaginary)
+Gregorian date Sunday, December 31, 1 BC."
+ (if (< date calendar-islamic-epoch)
+ (list 0 0 0) ; pre-Islamic date
+ (let* ((approx (/ (- date calendar-islamic-epoch)
+ 355)) ; approximation from below
+ (year ; search forward from the approximation
+ (+ approx
+ (calendar-sum y approx
+ (>= date (calendar-islamic-to-absolute
+ (list 1 1 (1+ y))))
+ 1)))
+ (month ; search forward from Muharram
+ (1+ (calendar-sum m 1
+ (> date
+ (calendar-islamic-to-absolute
+ (list m
+ (calendar-islamic-last-day-of-month
+ m year)
+ year)))
+ 1)))
+ (day ; calculate the day by subtraction
+ (- date
+ (1- (calendar-islamic-to-absolute (list month 1 year))))))
+ (list month day year))))
+
+;;;###cal-autoload
+(defun calendar-islamic-date-string (&optional date)
+ "String of Islamic date before sunset of Gregorian DATE.
+Returns the empty string if DATE is pre-Islamic.
+Defaults to today's date if DATE is not given.
+Driven by the variable `calendar-date-display-form'."
+ (let ((calendar-month-name-array calendar-islamic-month-name-array)
+ (islamic-date (calendar-islamic-from-absolute
+ (calendar-absolute-from-gregorian
+ (or date (calendar-current-date))))))
+ (if (< (calendar-extract-year islamic-date) 1)
+ ""
+ (calendar-date-string islamic-date nil t))))
+
+;;;###cal-autoload
+(defun calendar-islamic-print-date ()
+ "Show the Islamic calendar equivalent of the date under the cursor."
+ (interactive)
+ (let ((i (calendar-islamic-date-string (calendar-cursor-to-date t))))
+ (if (string-equal i "")
+ (message "Date is pre-Islamic")
+ (message "Islamic date (until sunset): %s" i))))
+
+(define-obsolete-function-alias 'calendar-print-islamic-date
+ 'calendar-islamic-print-date "23.1")
+
+(defun calendar-islamic-read-date ()
+ "Interactively read the arguments for an Islamic date command.
+Reads a year, month, and day."
+ (let* ((today (calendar-current-date))
+ (year (calendar-read
+ "Islamic calendar year (>0): "
+ (lambda (x) (> x 0))
+ (number-to-string
+ (calendar-extract-year
+ (calendar-islamic-from-absolute
+ (calendar-absolute-from-gregorian today))))))
+ (month-array calendar-islamic-month-name-array)
+ (completion-ignore-case t)
+ (month (cdr (assoc-string
+ (completing-read
+ "Islamic calendar month name: "
+ (mapcar 'list (append month-array nil))
+ nil t)
+ (calendar-make-alist month-array 1) t)))
+ (last (calendar-islamic-last-day-of-month month year))
+ (day (calendar-read
+ (format "Islamic calendar day (1-%d): " last)
+ (lambda (x) (and (< 0 x) (<= x last))))))
+ (list (list month day year))))
+
+;;;###cal-autoload
+(defun calendar-islamic-goto-date (date &optional noecho)
+ "Move cursor to Islamic DATE; echo Islamic date unless NOECHO is non-nil."
+ (interactive (calendar-islamic-read-date))
+ (calendar-goto-date (calendar-gregorian-from-absolute
+ (calendar-islamic-to-absolute date)))
+ (or noecho (calendar-islamic-print-date)))
+
+(define-obsolete-function-alias 'calendar-goto-islamic-date
+ 'calendar-islamic-goto-date "23.1")
+
+(defvar displayed-month) ; from calendar-generate
+(defvar displayed-year)
+
+;;;###holiday-autoload
+(defun holiday-islamic (month day string)
+ "Holiday on MONTH, DAY (Islamic) called STRING.
+If MONTH, DAY (Islamic) is visible, returns the corresponding
+Gregorian date as the list (((month day year) STRING)).
+Returns nil if it is not visible in the current calendar window."
+ ;; Islamic date corresponding to the center of the calendar window.
+ ;; Since the calendar displays 3 months at a time, there are approx
+ ;; 45 visible days either side of this date. Given the length of
+ ;; the Islamic months, this means up to two different months are
+ ;; visible either side of the central date.
+ (let* ((islamic-date (calendar-islamic-from-absolute
+ (calendar-absolute-from-gregorian
+ (list displayed-month 15 displayed-year))))
+ (m (calendar-extract-month islamic-date))
+ (y (calendar-extract-year islamic-date))
+ date)
+ (unless (< m 1) ; Islamic calendar doesn't apply
+ ;; Since converting to absolute dates can be a complex
+ ;; operation, we try to speed things up by excluding those date
+ ;; ranges that can't possibly be visible.
+ ;; We can view the situation (see above) as if we had a calendar
+ ;; window displaying 5 months at a time. When month m is
+ ;; central, months m-2:m+2 (modulo 12) might be visible.
+ ;; Recall from holiday-fixed that with a 3 month calendar
+ ;; window, November is special, because we can do a one-sided
+ ;; inclusion test. When November is central is when the end of
+ ;; year first appears on the calendar. Similarly, with a 5
+ ;; month window, October is special. When October is central is
+ ;; when the end of year first appears, and when January is
+ ;; central, October is no longer visible. October is visible
+ ;; when the central month is >= 8.
+ ;; Hence to test if any given month might be visible, we can
+ ;; shift things and ask about October.
+ ;; At the same time, we work out the appropriate year y to use.
+ (calendar-increment-month m y (- 10 month))
+ (and (> m 7) ; Islamic date might be visible
+ (calendar-date-is-visible-p
+ (setq date (calendar-gregorian-from-absolute
+ (calendar-islamic-to-absolute (list month day y)))))
+ (list (list date string))))))
+
+;;;###holiday-autoload
+(defun holiday-islamic-new-year ()
+ "Holiday entry for the Islamic New Year, if visible in the calendar window."
+ (let ((date (caar (holiday-islamic 1 1 "")))
+ (m displayed-month)
+ (y displayed-year))
+ (and date
+ (list (list date
+ (format "Islamic New Year %d"
+ (progn
+ (calendar-increment-month m y 1)
+ (calendar-extract-year
+ (calendar-islamic-from-absolute
+ (calendar-absolute-from-gregorian
+ (list m (calendar-last-day-of-month m y) y)
+ ))))))))))
+
+(autoload 'diary-list-entries-1 "diary-lib")
+
+;;;###diary-autoload
+(defun diary-islamic-list-entries ()
+ "Add any Islamic date entries from the diary file to `diary-entries-list'.
+Islamic date diary entries must be prefaced by `diary-islamic-entry-symbol'
+\(normally an `I'). The same `diary-date-forms' govern the style
+of the Islamic calendar entries, except that the Islamic month
+names cannot be abbreviated. The Islamic months are numbered
+from 1 to 12 with Muharram being 1 and 12 being Dhu al-Hijjah.
+If an Islamic date diary entry begins with `diary-nonmarking-symbol',
+the entry will appear in the diary listing, but will not be
+marked in the calendar. This function is provided for use with
+`diary-nongregorian-listing-hook'."
+ (diary-list-entries-1 calendar-islamic-month-name-array
+ diary-islamic-entry-symbol
+ 'calendar-islamic-from-absolute))
+
+(define-obsolete-function-alias 'list-islamic-diary-entries
+ 'diary-islamic-list-entries "23.1")
+
+(autoload 'calendar-mark-1 "diary-lib")
+
+;;;###diary-autoload
+(defun calendar-islamic-mark-date-pattern (month day year &optional color)
+ "Mark dates in calendar window that conform to Islamic date MONTH/DAY/YEAR.
+A value of 0 in any position is a wildcard. Optional argument COLOR is
+passed to `calendar-mark-visible-date' as MARK."
+ (calendar-mark-1 month day year 'calendar-islamic-from-absolute
+ 'calendar-islamic-to-absolute color))
+
+(define-obsolete-function-alias 'mark-islamic-calendar-date-pattern
+ 'calendar-islamic-mark-date-pattern "23.1")
+
+(autoload 'diary-mark-entries-1 "diary-lib")
+
+;;;###diary-autoload
+(defun diary-islamic-mark-entries ()
+ "Mark days in the calendar window that have Islamic date diary entries.
+Marks each entry in `diary-file' (or included files) visible in the calendar
+window. See `diary-islamic-list-entries' for more information."
+ (diary-mark-entries-1 'calendar-islamic-mark-date-pattern
+ calendar-islamic-month-name-array
+ diary-islamic-entry-symbol
+ 'calendar-islamic-from-absolute))
+
+(define-obsolete-function-alias
+ 'mark-islamic-diary-entries 'diary-islamic-mark-entries "23.1")
+
+(autoload 'diary-insert-entry-1 "diary-lib")
+
+;;;###cal-autoload
+(defun diary-islamic-insert-entry (arg)
+ "Insert a diary entry.
+For the Islamic date corresponding to the date indicated by point.
+Prefix argument ARG makes the entry nonmarking."
+ (interactive "P")
+ (diary-insert-entry-1 nil arg calendar-islamic-month-name-array
+ diary-islamic-entry-symbol
+ 'calendar-islamic-from-absolute))
+
+(define-obsolete-function-alias 'insert-islamic-diary-entry
+ 'diary-islamic-insert-entry "23.1")
+
+;;;###cal-autoload
+(defun diary-islamic-insert-monthly-entry (arg)
+ "Insert a monthly diary entry.
+For the day of the Islamic month corresponding to the date indicated by point.
+Prefix argument ARG makes the entry nonmarking."
+ (interactive "P")
+ (diary-insert-entry-1 'monthly arg calendar-islamic-month-name-array
+ diary-islamic-entry-symbol
+ 'calendar-islamic-from-absolute))
+
+(define-obsolete-function-alias 'insert-monthly-islamic-diary-entry
+ 'diary-islamic-insert-monthly-entry "23.1")
+
+;;;###cal-autoload
+(defun diary-islamic-insert-yearly-entry (arg)
+ "Insert an annual diary entry.
+For the day of the Islamic year corresponding to the date indicated by point.
+Prefix argument ARG makes the entry nonmarking."
+ (interactive "P")
+ (diary-insert-entry-1 'yearly arg calendar-islamic-month-name-array
+ diary-islamic-entry-symbol
+ 'calendar-islamic-from-absolute))
+(define-obsolete-function-alias
+ 'insert-yearly-islamic-diary-entry 'diary-islamic-insert-yearly-entry "23.1")
+
+(defvar date)
+
+;; To be called from diary-sexp-entry, where DATE, ENTRY are bound.
+;;;###diary-autoload
+(defun diary-islamic-date ()
+ "Islamic calendar equivalent of date diary entry."
+ (let ((i (calendar-islamic-date-string date)))
+ (if (string-equal i "")
+ "Date is pre-Islamic"
+ (format "Islamic date (until sunset): %s" i))))
+
+(provide 'cal-islam)
+
+;; arch-tag: a951b6c1-6f47-48d5-bac3-1b505cd719f7
+;;; cal-islam.el ends here
HCoop / bpt / emacs.git / blobdiff