Rationalize calendar handling of day and month abbrev-arrays.

* lisp/calendar/calendar.el (calendar-customized-p): New function.
(calendar-abbrev-construct, calendar-make-alist): Change what it does.
(calendar-day-name-array, calendar-month-name-array): Doc fix.
Add :set function.
(calendar-abbrev-length, calendar-day-abbrev-array)
(calendar-month-abbrev-array): Make defcustoms, with appropriate :set.
(calendar-day-abbrev-array, calendar-month-abbrev-array):
Elements may no longer be nil.
(calendar-day-name, calendar-month-name):
Update for changed nature of abbrev arrays.
* calendar/diary-lib.el (diary-name-pattern):
Update for changed nature of abbrev arrays.
(diary-mark-entries-1): Update calendar-make-alist calls.
(diary-font-lock-date-forms): Doc fix for changed abbrev arrays.
* calendar/cal-html.el (cal-html-day-abbrev-array):
Simply inherit from calendar-day-abbrev-array.

* etc/NEWS: Mention this.

5 files changed, 187 insertions, 97 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 9889067fb87..9a906889530 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -473,6 +473,10 @@ See the variable `appt-warning-time-regexp'.
 *** New function `diary-hebrew-birthday'.
 
 ---
+*** Elements of `calendar-day-abbrev-array' and `calendar-month-abbrev-array'
+may no longer be nil, but must all be strings.
+
+---
 *** The obsolete (since Emacs 22.1) method of enabling the appt package
 by adding appt-make-list to diary-hook has been removed.  Use appt-activate.
 
diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 1fc7cc88f8d..fa61c6913c2 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,23 @@
+2011-05-18  Glenn Morris  <rgm@gnu.org>
+
+	Rationalize calendar handling of day and month abbrev-arrays.
+	* calendar/calendar.el (calendar-customized-p): New function.
+	(calendar-abbrev-construct, calendar-make-alist): Change what it does.
+	(calendar-day-name-array, calendar-month-name-array): Doc fix.
+	Add :set function.
+	(calendar-abbrev-length, calendar-day-abbrev-array)
+	(calendar-month-abbrev-array): Make defcustoms, with appropriate :set.
+	(calendar-day-abbrev-array, calendar-month-abbrev-array):
+	Elements may no longer be nil.
+	(calendar-day-name, calendar-month-name):
+	Update for changed nature of abbrev arrays.
+	* calendar/diary-lib.el (diary-name-pattern):
+	Update for changed nature of abbrev arrays.
+	(diary-mark-entries-1): Update calendar-make-alist calls.
+	(diary-font-lock-date-forms): Doc fix for changed abbrev arrays.
+	* calendar/cal-html.el (cal-html-day-abbrev-array):
+	Simply inherit from calendar-day-abbrev-array.
+
 2011-05-17  Stefan Monnier  <monnier@iro.umontreal.ca>
 
 	* progmodes/grep.el (grep-mode): Disable default
diff --git a/lisp/calendar/cal-html.el b/lisp/calendar/cal-html.el
index bcc19ccda0b..580b953170c 100644
--- a/lisp/calendar/cal-html.el
+++ b/lisp/calendar/cal-html.el
@@ -54,11 +54,16 @@
   :type 'integer
   :group 'calendar-html)
 
-(defcustom cal-html-day-abbrev-array
-  (calendar-abbrev-construct calendar-day-abbrev-array
-                             calendar-day-name-array)
+(defcustom cal-html-day-abbrev-array calendar-day-abbrev-array
   "Array of seven strings for abbreviated day names (starting with Sunday)."
-  :type '(vector string string string string string string string)
+  :set-after '(calendar-day-abbrev-array)
+  :type '(vector (string :tag "Sun")
+                 (string :tag "Mon")
+                 (string :tag "Tue")
+                 (string :tag "Wed")
+                 (string :tag "Thu")
+                 (string :tag "Fri")
+                 (string :tag "Sat"))
   :group 'calendar-html)
 
 (defcustom cal-html-css-default
diff --git a/lisp/calendar/calendar.el b/lisp/calendar/calendar.el
index e81eb554458..fa19d1ffe14 100644
--- a/lisp/calendar/calendar.el
+++ b/lisp/calendar/calendar.el
@@ -2034,18 +2034,40 @@ is a string to insert in the minibuffer before reading."
     value))
 
 
-(defvar calendar-abbrev-length 3
-  "*Length of abbreviations to be used for day and month names.
-See also `calendar-day-abbrev-array' and `calendar-month-abbrev-array'.")
+(defun calendar-customized-p (symbol)
+  "Return non-nil if SYMBOL has been customized."
+  (and (default-boundp symbol)
+       (let ((standard (get symbol 'standard-value)))
+         (and standard
+              (not (equal (eval (car standard)) (default-value symbol)))))))
+
+(defun calendar-abbrev-construct (full)
+  "From sequence FULL, return a vector of abbreviations.
+Each abbreviation is no longer than `calendar-abbrev-length' characters."
+  (apply 'vector (mapcar
+                  (lambda (f)
+                    (substring f 0 (min calendar-abbrev-length (length f))))
+                  full)))
 
-;; FIXME does it have to start from Sunday?
 (defcustom calendar-day-name-array
   ["Sunday" "Monday" "Tuesday" "Wednesday" "Thursday" "Friday" "Saturday"]
-  "Array of capitalized strings giving, in order, the day names.
+  "Array of capitalized strings giving, in order from Sunday, the day names.
 The first two characters of each string will be used to head the
-day columns in the calendar.  See also the variable
-`calendar-day-abbrev-array'."
+day columns in the calendar.
+If you change this without using customize after the calendar has loaded,
+then you may also want to change `calendar-day-abbrev-array'."
   :group 'calendar
+  :initialize 'custom-initialize-default
+  :set (lambda (symbol value)
+         (let ((dcustomized (calendar-customized-p 'calendar-day-abbrev-array))
+               (hcustomized (calendar-customized-p 'cal-html-day-abbrev-array)))
+           (set symbol value)
+           (or dcustomized
+               (setq calendar-day-abbrev-array
+                     (calendar-abbrev-construct calendar-day-name-array)))
+           (and (not hcustomized)
+                (boundp 'cal-html-day-abbrev-array)
+                (setq cal-html-day-abbrev-array calendar-day-abbrev-array))))
   :type '(vector (string :tag "Sunday")
                  (string :tag "Monday")
                  (string :tag "Tuesday")
@@ -2054,23 +2076,74 @@ day columns in the calendar.  See also the variable
                  (string :tag "Friday")
                  (string :tag "Saturday")))
 
-(defvar calendar-day-abbrev-array
-  [nil nil nil nil nil nil nil]
-  "*Array of capitalized strings giving the abbreviated day names.
+(defcustom calendar-abbrev-length 3
+  "Default length of abbreviations to use for day and month names.
+If you change this without using customize after the calendar has loaded,
+then you may also want to change `calendar-day-abbrev-array' and
+`calendar-month-abbrev-array'."
+  :group 'calendar
+  :initialize 'custom-initialize-default
+  :set (lambda (symbol value)
+         (let ((dcustomized (calendar-customized-p 'calendar-day-abbrev-array))
+               (mcustomized (calendar-customized-p
+                             'calendar-month-abbrev-array))
+               (hcustomized (calendar-customized-p 'cal-html-day-abbrev-array)))
+           (set symbol value)
+           (or dcustomized
+               (setq calendar-day-abbrev-array
+                     (calendar-abbrev-construct calendar-day-name-array)))
+           (or mcustomized
+               (setq calendar-month-abbrev-array
+                     (calendar-abbrev-construct calendar-month-name-array)))
+           (and (not hcustomized)
+                (boundp 'cal-html-day-abbrev-array)
+                (setq cal-html-day-abbrev-array calendar-day-abbrev-array))))
+  :type 'integer)
+
+(defcustom calendar-day-abbrev-array
+  (calendar-abbrev-construct calendar-day-name-array)
+  "Array of capitalized strings giving the abbreviated day names.
 The order should be the same as that of the full names specified
 in `calendar-day-name-array'.  These abbreviations may be used
 instead of the full names in the diary file.  Do not include a
 trailing `.' in the strings specified in this variable, though
-you may use such in the diary file.  If any element of this array
-is nil, then the abbreviation will be constructed as the first
-`calendar-abbrev-length' characters of the corresponding full name.")
+you may use such in the diary file.  By default, each string is
+the first `calendar-abbrev-length' characters of the corresponding
+full name."
+  :group 'calendar
+  :initialize 'custom-initialize-default
+  :set-after '(calendar-abbrev-length calendar-day-name-array)
+  :set (lambda (symbol value)
+         (let ((hcustomized (calendar-customized-p 'cal-html-day-abbrev-array)))
+           (set symbol value)
+           (and (not hcustomized)
+                (boundp 'cal-html-day-abbrev-array)
+                (setq cal-html-day-abbrev-array calendar-day-abbrev-array))))
+  :type '(vector (string :tag "Sun")
+                 (string :tag "Mon")
+                 (string :tag "Tue")
+                 (string :tag "Wed")
+                 (string :tag "Thu")
+                 (string :tag "Fri")
+                 (string :tag "Sat"))
+  ;; Made defcustom, changed defaults from nil nil...
+  :version "24.1")
 
 (defcustom calendar-month-name-array
   ["January" "February" "March"     "April"   "May"      "June"
    "July"    "August"   "September" "October" "November" "December"]
   "Array of capitalized strings giving, in order, the month names.
-See also the variable `calendar-month-abbrev-array'."
+If you change this without using customize after the calendar has loaded,
+then you may also want to change `calendar-month-abbrev-array'."
   :group 'calendar
+  :initialize 'custom-initialize-default
+  :set (lambda (symbol value)
+         (let ((mcustomized (calendar-customized-p
+                            'calendar-month-abbrev-array)))
+           (set symbol value)
+           (or mcustomized
+               (setq calendar-month-abbrev-array
+                     (calendar-abbrev-construct calendar-month-name-array)))))
   :type '(vector (string :tag "January")
                  (string :tag "February")
                  (string :tag "March")
@@ -2084,46 +2157,54 @@ See also the variable `calendar-month-abbrev-array'."
                  (string :tag "November")
                  (string :tag "December")))
 
-(defvar calendar-month-abbrev-array
-  [nil nil nil nil nil nil nil nil nil nil nil nil]
- "*Array of capitalized strings giving the abbreviated month names.
+(defcustom calendar-month-abbrev-array
+  (calendar-abbrev-construct calendar-month-name-array)
+ "Array of capitalized strings giving the abbreviated month names.
 The order should be the same as that of the full names specified
 in `calendar-month-name-array'.  These abbreviations are used in
 the calendar menu entries, and can also be used in the diary
 file.  Do not include a trailing `.' in the strings specified in
-this variable, though you may use such in the diary file.  If any
-element of this array is nil, then the abbreviation will be
-constructed as the first `calendar-abbrev-length' characters of the
-corresponding full name.")
-
-(defun calendar-make-alist (sequence &optional start-index filter abbrevs)
-  "Make an assoc list corresponding to SEQUENCE.
-Each element of sequence will be associated with an integer, starting
-from 1, or from START-INDEX if that is non-nil.  If a sequence ABBREVS
-is supplied, the function `calendar-abbrev-construct' is used to
-construct abbreviations corresponding to the elements in SEQUENCE.
-Each abbreviation is entered into the alist with the same
-association index as the full name it represents.
-If FILTER is provided, apply it to each key in the alist."
-  (let ((index 0)
-        (offset (or start-index 1))
-        (aseq (if abbrevs (calendar-abbrev-construct abbrevs sequence)))
-        (aseqp (if abbrevs (calendar-abbrev-construct abbrevs sequence
-                                                      'period)))
-        alist elem)
-    (dotimes (i (length sequence) (reverse alist))
-      (setq index (+ i offset)
-            elem (elt sequence i)
-            alist
-            (cons (cons (if filter (funcall filter elem) elem) index) alist))
-      (if aseq
-          (setq elem (elt aseq i)
-                alist (cons (cons (if filter (funcall filter elem) elem)
-                                  index) alist)))
-      (if aseqp
-          (setq elem (elt aseqp i)
-                alist (cons (cons (if filter (funcall filter elem) elem)
-                                  index) alist))))))
+this variable, though you may use such in the diary file.  By
+default, each string is the first ``calendar-abbrev-length'
+characters of the corresponding full name."
+ :group 'calendar
+ :set-after '(calendar-abbrev-length calendar-month-name-array)
+ :type '(vector (string :tag "Jan")
+                (string :tag "Feb")
+                (string :tag "Mar")
+                (string :tag "Apr")
+                (string :tag "May")
+                (string :tag "Jun")
+                (string :tag "Jul")
+                (string :tag "Aug")
+                (string :tag "Sep")
+                (string :tag "Oct")
+                (string :tag "Nov")
+                (string :tag "Dec"))
+ ;; Made defcustom, changed defaults from nil nil...
+ :version "24.1")
+
+(defun calendar-make-alist (sequence &optional start-index filter
+                                     &rest sequences)
+  "Return an association list corresponding to SEQUENCE.
+Associates each element of SEQUENCE with an incremented integer,
+starting from START-INDEX (default 1).  Applies the function FILTER,
+if provided, to each key in the alist.  Repeats the process, with
+indices starting from START-INDEX each time, for any remaining
+arguments SEQUENCES."
+  (or start-index (setq start-index 1))
+  (let (index alist)
+    (mapc (lambda (seq)
+            (setq index start-index)
+            (mapc (lambda (elem)
+                    (setq alist (cons
+                                 (cons (if filter (funcall filter elem) elem)
+                                       index)
+                                 alist)
+                          index (1+ index)))
+                  seq))
+          (append (list sequence) sequences))
+    (reverse alist)))
 
 (defun calendar-read-date (&optional noday)
   "Prompt for Gregorian date.  Return a list (month day year).
@@ -2162,23 +2243,6 @@ Negative years are interpreted as years BC; -1 being 1 BC, and so on."
   (+ (* 12 (- yr2 yr1))
      (- mon2 mon1)))
 
-(defun calendar-abbrev-construct (abbrev full &optional period)
-  "Internal calendar function to return a complete abbreviation array.
-ABBREV is an array of abbreviations, FULL the corresponding array
-of full names.  The return value is the ABBREV array, with any nil
-elements replaced by the first three characters taken from the
-corresponding element of FULL.  If optional argument PERIOD is non-nil,
-each element returned has a final `.' character."
-  (let (elem array name)
-    (dotimes (i (length full))
-      (setq name (aref full i)
-            elem (or (aref abbrev i)
-                     (substring name 0
-                                (min calendar-abbrev-length (length name))))
-            elem (format "%s%s" elem (if period "." ""))
-            array (append array (list elem))))
-    (vconcat array)))
-
 (defvar calendar-font-lock-keywords
   `((,(concat (regexp-opt (mapcar 'identity calendar-month-name-array) t)
               " -?[0-9]+")
@@ -2204,10 +2268,7 @@ be an integer in the range 0 to 6 corresponding to the day of the
 week.  Day names are taken from the variable `calendar-day-name-array',
 unless the optional argument ABBREV is non-nil, in which case
 the variable `calendar-day-abbrev-array' is used."
-  (aref (if abbrev
-            (calendar-abbrev-construct calendar-day-abbrev-array
-                                       calendar-day-name-array)
-          calendar-day-name-array)
+  (aref (if abbrev calendar-day-abbrev-array calendar-day-name-array)
         (if absolute date (calendar-day-of-week date))))
 
 (defun calendar-month-name (month &optional abbrev)
@@ -2216,10 +2277,7 @@ Months are numbered from one.  Month names are taken from the
 variable `calendar-month-name-array', unless the optional
 argument ABBREV is non-nil, in which case
 `calendar-month-abbrev-array' is used."
-  (aref (if abbrev
-            (calendar-abbrev-construct calendar-month-abbrev-array
-                                       calendar-month-name-array)
-          calendar-month-name-array)
+  (aref (if abbrev calendar-month-abbrev-array calendar-month-name-array)
         (1- month)))
 
 (defun calendar-day-of-week (date)
diff --git a/lisp/calendar/diary-lib.el b/lisp/calendar/diary-lib.el
index 62da7579d50..f21247e9c93 100644
--- a/lisp/calendar/diary-lib.el
+++ b/lisp/calendar/diary-lib.el
@@ -1250,19 +1250,15 @@ should ensure that all relevant variables are set.
 
 (defun diary-name-pattern (string-array &optional abbrev-array paren)
   "Return a regexp matching the strings in the array STRING-ARRAY.
-If the optional argument ABBREV-ARRAY is present, then the function
-`calendar-abbrev-construct' is used to construct abbreviations from the
-two supplied arrays.  The returned regexp will then also match these
-abbreviations, with or without final `.' characters.  If the optional
-argument PAREN is non-nil, the regexp is surrounded by parentheses."
+If the optional argument ABBREV-ARRAY is present, the regexp
+also matches the supplied abbreviations, with or without final `.'
+characters.  If the optional argument PAREN is non-nil, surrounds
+the regexp with parentheses."
   (regexp-opt (append string-array
+                      abbrev-array
                       (if abbrev-array
-                          (calendar-abbrev-construct abbrev-array
-                                                     string-array))
-                      (if abbrev-array
-                          (calendar-abbrev-construct abbrev-array
-                                                     string-array
-                                                     'period))
+                          (mapcar (lambda (e) (format "%s." e))
+                                  abbrev-array))
                       nil)
               paren))
 
@@ -1363,7 +1359,11 @@ function that converts absolute dates to dates of the appropriate type.  "
                  (cdr (assoc-string dd-name
                                     (calendar-make-alist
                                      calendar-day-name-array
-                                     0 nil calendar-day-abbrev-array) t)) marks)
+                                     0 nil calendar-day-abbrev-array
+                                     (mapcar (lambda (e)
+                                               (format "%s." e))
+                                             calendar-day-abbrev-array))
+                                    t)) marks)
               (if mm-name
                   (setq mm
                         (if (string-equal mm-name "*") 0
@@ -1372,7 +1372,11 @@ function that converts absolute dates to dates of the appropriate type.  "
                                 (if months (calendar-make-alist months)
                                   (calendar-make-alist
                                    calendar-month-name-array
-                                   1 nil calendar-month-abbrev-array)) t)))))
+                                   1 nil calendar-month-abbrev-array
+                                   (mapcar (lambda (e)
+                                             (format "%s." e))
+                                           calendar-month-abbrev-array)))
+                                t)))))
               (funcall markfunc mm dd yy marks))))))))
 
 ;;;###cal-autoload
@@ -2307,11 +2311,10 @@ Prefix argument ARG makes the entry nonmarking."
 
 (defun diary-font-lock-date-forms (month-array &optional symbol abbrev-array)
   "Create font-lock patterns for `diary-date-forms' using MONTH-ARRAY.
-If given, optional SYMBOL must be a prefix to entries.
-If optional ABBREV-ARRAY is present, the abbreviations constructed
-from this array by the function `calendar-abbrev-construct' are
-matched (with or without a final `.'), in addition to the full month
-names."
+If given, optional SYMBOL must be a prefix to entries.  If
+optional ABBREV-ARRAY is present, also matches the abbreviations
+from this array (with or without a final `.'), in addition to the
+full month names."
   (let ((dayname (diary-name-pattern calendar-day-name-array
                                      calendar-day-abbrev-array t))
         (monthname (format "\\(%s\\|\\*\\)"