Flavio S. Glock wrote: > Sets of type 4 are 'huge sets'. These have an 'unknown' count. The count > can be thousands or even millions of dates, but it is not infinite.
- or two or three - > Before version 0.10, you would run out of memory if you specified > something like "all seconds in the century". > Now, the program will just go on normally - it creates a 'huge set'. And > it doesn't attempt to count the set elements. Would there be some way we could 'guess' if it's loo large to count? Or maybe if a count is requested, we count 10,000 and then return undef if there's more? I'm thinking there would be a lot of recurrences such as 'every tuesday' with restraints such as 'in 2003'. This is easily countable and probably useful. The 'guess' part would be to look at the recurrence and check it's 'density'. With the occurrence above, the density is 1/week. Given a start and end date, we could calculate this for a large number of years. Lets say this module doesn't return counts over 10,000. We build in yearly guestimates for our density denominators. The week guestimate is 52. So we can count the elements for (range as years in float)/52 recurrences. If we have a recurrence of 'every second' then the yearly guestimate is 60*60*24*356.25. Now we can take our (range as years in float) and divide it by our yearly guestimate. If the result is over 10,000 we return undef. While all this is a heap of code, we can quickly see if it's worth counting the actual occurrences. ALSO If we go this path or not, I'd prefer not to get plain undef back. I'd like an indication that it was 'too hard to count', or that it was 'over 10,000'. Cheers! Rick
