Talk:Discordian date: Difference between revisions
Leap Years
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According to wikipedia page, every fourth year is a leap year. This diverges from the Gregorian, which has special rules for years divisible by 100. Should the code respect this or just ignore it? --[[User:Oenone|Oenone]] 08:27, 21 January 2011 (UTC)
: Match the Gregorian year definition, as trying to deal with other kinds of calendar turns the task into a ridiculously awkward one. –[[User:Dkf|Donal Fellows]] 09:30, 21 January 2011 (UTC)
:Normally the calendar matches the Gregorian. However, there is a variant (less common than the normal one) which does diverge from the Gregorian as mentioned above (due to a slight ambiguity in the Principia Discordia). The task should probably just use the Gregorian-based version, although it should be allowed for a code to support both versions if someone want to write such a code, too. --[[User:Zzo38|Zzo38]] ([[User talk:Zzo38|talk]]) 02:20, 13 October 2015 (UTC)
== D Entry ==
Some rationale for the changes in the D entry:
- For browser screens with a not high resolution it's better to keep lines of code short. For Rosettacode code I use about 72-73 chars max for line.
- To keep code readable it's usually better to keep the then/else clauses on their own lines.
- Variables should be immutable (or const, where immutable is not possible) unless they have to mutate or unless some compiler bug (or the design of ranges) makes immutable/const unusable.
- The scope of variables should be minimized. So arrays like 'seasons' can go in the function scope and avoid polluting the module namespace.
: Since these constants are fundamental to Discordian dates, they are more useful in the module namespace: other modules could query them and new functions added to the module would be able to see them immediately. [[User:Fwend|Fwend]] ([[User talk:Fwend|talk]]) 15:15, 25 July 2013 (UTC)
- Some variable names like dYear now have an upper case in the middle to underline their inner words. It's normal D style.
- Currently the format() function is not pure nor nothrow, but maybe in future it will become pure. So I keep some commented out code like /*pure*/ that are meant to be replaced by code in future if and when Phobos improves (I replace such comments all the time in Rosettacode entries because Phobos keeps improving).
== Broken examples ==
It seems this task has been rather poorly implemented, possibly because one of the original examples was incorrect, and others have just translated that directly. I've marked about a dozen as incorrect so far (some of which have already been fixed), but I'm fairly sure there are more that are wrong.
The easiest mistake to spot is anything that calculates the day number with a simple modulo operation since that is bound to give you a zero day at some point, which would never be correct. Examples that appear to have this mistake that I haven't flagged yet include [[Discordian_date#Euphoria|Euphoria]], [[Discordian_date#Mathematica|Mathematica]], [[Discordian_date#PureBasic|PureBasic]] and [[Discordian_date#Racket|Racket]]. I don't want to mark anything incorrect that I haven't been able to verify directly, though, so I'm hoping others can confirm whether those are right or wrong.
The handling of leap years seem to be another source of confusion, so that's also something worth testing thoroughly if you want to be sure that your example is truly correct.
--[[User:J4 james|j4_james]] ([[User talk:J4 james|talk]]) 12:38, 7 October 2015 (UTC)
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