Re: Calendar hack: Displaying ISO weeks, update for emacs 22, the real update
[EMAIL PROTECTED] (Edward M. Reingold) writes: [EMAIL PROTECTED] (Edward M. Reingold) writes: How do you know that the holidays are correct when the calendar has more than 3 months? Do you have a way to check, say, the dates of lunar phases, Easter, Chinese New Year, Yom Kippur, Islamic New Year, solstices/equinoxes? You will see SOME holidays (or diary entries) but not all that apply to the months displayed. I now see that I misread this question: I read it as it was about the hack as it is implemented now and how I know that the hack works with non-fixed holidays, not about my comment about the non-implemented dynamically sized calendar. The answer to the question above is: I don't know, and that is why I wrote that I had to specifically test for it if it were implemented, for instance in the way that RMS wrote in [EMAIL PROTECTED]. [...] if the window is 5 months wide, they could be visible and the command to list or highlight all holidays will miss them. Almost all of the non-trivial holidays/diary entries would suffer in the same way, so rewriting the code properly to display a wider window means modifying almost every holiday/diary function in some (usually non-obvious) way. That supports the point I was trying to make. Since this feature is not implemented I do not have to bother with it in the modified code - as the current calendar is static. Affi ___ gnu-emacs-sources mailing list gnu-emacs-sources@gnu.org http://lists.gnu.org/mailman/listinfo/gnu-emacs-sources
Re: Calendar hack: Displaying ISO weeks, update for emacs 22, the real update
It sounds like we should systematically replace such code with something more robust. It could use two variables, calendar-first-visible-month and calendar-last-visible-month, to indicate the range that is visible. Yes, something like that; but it is not always that simple; I used that example because it came from code that the poster has modifed for his use. ___ gnu-emacs-sources mailing list gnu-emacs-sources@gnu.org http://lists.gnu.org/mailman/listinfo/gnu-emacs-sources
Re: Calendar hack: Displaying ISO weeks, update for emacs 22
[EMAIL PROTECTED] writes: Alf-Ivar Holm [EMAIL PROTECTED] writes: Could you give me _one_ function that would break? The displayed calendar is quite static, e.g. it does not support dynamic display of months when changing the width of the window (I could easily fit 5 months, included week numbers, on my screen if I do a horizontal maximization of my calendar window), a functionality I would have had to specifically test for if it were present. When it comes to calculating a date I can't see why the visual representation of the calendar matters, e.g. the date structures is luckily not dependent of what is displayed in the buffer. Code that will break: all the holiday determination for non-trivial holidays. Ok, I'l discuss that in the other (sub) thread. This is the same thing I told you years ago: To determine the which diary entries or holidays are in the visible range, the 3-month size of the window is assumed; thus if you write the (trivial) loops to get, say, a 5-month calendar window, the holidays will not be properly determined or highlighted. The same is true for diary entries. What I was trying to say with the 5-month comment was that IF such functionality existed there would probably more work on my part (as well). With the calendar being static, it is quite easy to add visual stuff, like the week display hack. Also, when you ask for information about a date under the cursor (holidays, diary entries, other calendars, sunset, etc, etc), the code needs to translate the physical cursor position to a date. Ok, but the postion of the dates are not changed by the addition of the week numbers, which is display in the 5 character empty space to the right of each month. This is why the need for a seperate face is needed (which again prompted this update) as the calendar gets a bit cramped with the week numbers added. There is another 5 characters on the left that would be nice to use to put some air between the week number of one month and the dates of the next, but *that* would change the positions of the dates and therefore need tweeking of the date calculation. (This is left as an exercise to someone else.) That translation process assumes a rigid form to the calendar window--adding the ISO week or stretching the calendar to 5 months, say, screws up that translation process. I agree that adding the stretching is a major rewrite (that I admit that I would have liked to see implemented.) The problem with redoing the calendar code to include extraneous information (like ISO weeks) or changing the number of months displayed is that the assumptions about the window's contents are intrinsic to many parts of the code and very hard to ferret out. It is very easy to make such changes so that work with YOUR PARTICULAR calendar usage, but it would require a MAJOR rewriting of the code to make it work generally. Ok, I might have been a bit hasty in my comment about the visual representation, but if the code only refers to positions, and not content, the hack would still work as the date placements are not changed. Sorry, but when the heart of the code was written in the mid 1980s, all that was generally available were 80-column aasci screens. I still use 80 columns in my emacs windows, but as I display my calendar in a separat window I could sometimes stretch it sideways if I wanted to plan something which stretch over more than 3 months - that's the idea I had about the 5 month comment. Affi ___ gnu-emacs-sources mailing list gnu-emacs-sources@gnu.org http://lists.gnu.org/mailman/listinfo/gnu-emacs-sources
Re: Calendar hack: Displaying ISO weeks, update for emacs 22, the real update
[EMAIL PROTECTED] (Edward M. Reingold) writes: AH == Alf-Ivar Holm [EMAIL PROTECTED] writes: AH I should point out as this is titled a hack and I do not have have a AH test suite I will not guarantee that it works in all environments, BUT AH I have used it with extensive diary usage, and with the use of AH Norwegian names, holidays, and calendar set up without any problems AH (except for eventual changes in functions/variables when a new emacs AH arrived, e.g. v. 22) for 10 years. Despite what the calendar author How do you know that the holidays are correct when the calendar has more than 3 months? Do you have a way to check, say, the dates of lunar phases, Easter, Chinese New Year, Yom Kippur, Islamic New Year, solstices/equinoxes? You will see SOME holidays (or diary entries) but not all that apply to the months displayed. I admit that I don't use many of those, but I have got Easter, which I had to modify to fit to the Norwegian Easter celebration¹. I have got this in the sitestart.el, again based on your code: (defun local-holiday-easter-etc () List of dates related to Easter in Norway, as visible in calendar window. (if (and ( displayed-month 5)) nil;; Ash Wednesday, Good Friday, and Easter are not visible. (let* ((century (1+ (/ displayed-year 100))) (shifted-epact;; Age of moon for April 5... (% (+ 14 (* 11 (% displayed-year 19));; ...by Nicaean rule (- ;; ...corrected for the Gregorian century rule (/ (* 3 century) 4)) (/;; ...corrected for Metonic cycle inaccuracy. (+ 5 (* 8 century)) 25) (* 30 century));; Keeps value positive. 30)) (adjusted-epact ;; Adjust for 29.5 day month. (if (or (= shifted-epact 0) (and (= shifted-epact 1) ( 10 (% displayed-year 19 (1+ shifted-epact) shifted-epact)) (paschal-moon ;; Day after the full moon on or after March 21. (- (calendar-absolute-from-gregorian (list 4 19 displayed-year)) adjusted-epact)) (abs-easter (calendar-dayname-on-or-before 0 (+ paschal-moon 7))) (mandatory (list (list (calendar-gregorian-from-absolute (- abs-easter 7)) Palmesøndag) (list (calendar-gregorian-from-absolute (- abs-easter 3)) Skjærtorsdag) (list (calendar-gregorian-from-absolute (- abs-easter 2)) Langfredag) (list (calendar-gregorian-from-absolute abs-easter) 1. påskedag) (list (calendar-gregorian-from-absolute (+ abs-easter 1)) 2. påskedag) (list (calendar-gregorian-from-absolute (+ abs-easter 39)) Himmelspretten) (list (calendar-gregorian-from-absolute (+ abs-easter 49)) 1. pinsedag) (list (calendar-gregorian-from-absolute (+ abs-easter 50)) 2. pinsedag))) (output-list (filter-visible-calendar-holidays mandatory))) (if all-christian-calendar-holidays (setq output-list (append (filter-visible-calendar-holidays optional) output-list))) output-list))) (eval-after-load holidays '(fset 'holiday-easter-etc 'local-holiday-easter-etc)) And this works as expected (by me), e.g. the Easter of 2007 is shown here, with the cursor on Easter Sunday (1. påskedag): http://pogostick.net/~affi/Screendump-Calendar-Easter2007.png The code won't generally die ungracefully, but the the output will NOT be right. Yes, that is of course harder to debug. Affi ¹) We only got 2 and half work day each Easter, with the day off on the day after Easter Sunday as well. We basically don't work at all at Easter. ___ gnu-emacs-sources mailing list gnu-emacs-sources@gnu.org http://lists.gnu.org/mailman/listinfo/gnu-emacs-sources
Re: Calendar hack: Displaying ISO weeks, update for emacs 22, the real update
AH == Alf-Ivar Holm [EMAIL PROTECTED] writes: AH (defun local-holiday-easter-etc () List of dates related to Easter in AH Norway, as visible in calendar window. (if (and ( displayed-month AH 5)) nil;; Ash Wednesday, Good Friday, and Easter are not visible. This a good example of why the wider window can cause erroneous results. The test (if ( displayed-month 5) checks if the center of the 3 month window is beyond May, in which case (as the comment from my code says!) Ash Wednesday, Good Friday, and Easter cannot be visibible because they occur in Feb/Mar/Apr. But if the window is 5 months wide, they could be visible and the command to list or highlight all holidays will miss them. Almost all of the non-trivial holidays/diary entries would suffer in the same way, so rewriting the code properly to display a wider window means modifying almost every holiday/diary function in some (usually non-obvious) way. -- Professor Edward M. ReingoldEmail: [EMAIL PROTECTED] Department of Computer Science Voice: (312) 567-3309 Illinois Institute of TechnologyAssistant: (312) 567-5152 Stuart Building Fax: (312) 567-5067 10 West 31st Street, Suite 236 Chicago, IL 60616-3729 U.S.A. ___ gnu-emacs-sources mailing list gnu-emacs-sources@gnu.org http://lists.gnu.org/mailman/listinfo/gnu-emacs-sources
Re: Calendar hack: Displaying ISO weeks, update for emacs 22, the real update
How do you know that the holidays are correct when the calendar has more than 3 months? Do you have a way to check, say, the dates of lunar phases, Easter, Chinese New Year, Yom Kippur, Islamic New Year, solstices/equinoxes? You will see SOME holidays (or diary entries) but not all that apply to the months displayed. One easy way to check is to run the standard calendar code (without this customization) and see if it indicates the same holidays. ___ gnu-emacs-sources mailing list gnu-emacs-sources@gnu.org http://lists.gnu.org/mailman/listinfo/gnu-emacs-sources
Re: Calendar hack: Displaying ISO weeks, update for emacs 22, the real update
The test (if ( displayed-month 5) checks if the center of the 3 month window is beyond May, in which case (as the comment from my code says!) Ash Wednesday, Good Friday, and Easter cannot be visibible because they occur in Feb/Mar/Apr. It sounds like we should systematically replace such code with something more robust. It could use two variables, calendar-first-visible-month and calendar-last-visible-month, to indicate the range that is visible. If someone wants to work on this now, that would be useful. But we should not install such changes until after Emacs 22 is released. ___ gnu-emacs-sources mailing list gnu-emacs-sources@gnu.org http://lists.gnu.org/mailman/listinfo/gnu-emacs-sources
Re: Calendar hack: Displaying ISO weeks, update for emacs 22
[EMAIL PROTECTED] (Edward M. Reingold) writes: This kind of modification of the shape of the calendar window will break many things in the determination of holidays and diary entries. It is not recommended! Yes, you told me 10 years ago, but as you have not yet provided me with any proof and I have not seen any of these functions break, I post it in case anyone else would like to have it. It is trivial to generate that look, but many, many functions would need to be modified to do the necessary interpretation of teh modified calendar buffer. Could you give me _one_ function that would break? The displayed calendar is quite static, e.g. it does not support dynamic display of months when changing the width of the window (I could easily fit 5 months, included week numbers, on my screen if I do a horizontal maximization of my calendar window), a functionality I would have had to specifically test for if it were present. When it comes to calculating a date I can't see why the visual representation of the calendar matters, e.g. the date structures is luckily not dependent of what is displayed in the buffer. Affi ___ gnu-emacs-sources mailing list gnu-emacs-sources@gnu.org http://lists.gnu.org/mailman/listinfo/gnu-emacs-sources
Re: Calendar hack: Displaying ISO weeks, update for emacs 22
Richard Stallman wrote: We took out `facemenu-unlisted-faces' because it was a no-op, it did nothing. We were not sure it was worth reimplementing the functionality. But now I see that we should. Why? The only way Affi's calendar-hack.el uses it is: (add-to-list 'facemenu-unlisted-faces 'calendar-week-face) (add-to-list 'facemenu-unlisted-faces 'calendar-header-face) (add-to-list 'facemenu-unlisted-faces 'calendar-sunday-face) Simply commenting that out -- or for older Emacs versions, protecting it inside (with (boundp 'facemenu-unlisted-faces) ...) -- should be enough. In any case, the face won't be added to facemenu-listed-faces, which achieves the desired result. -- Kevin ___ gnu-emacs-sources mailing list gnu-emacs-sources@gnu.org http://lists.gnu.org/mailman/listinfo/gnu-emacs-sources
