Why couldn't you do something like this? It is type stable:
using Base.Dates
leapDay = isleapyear(yr) ? Date(yr, 2, 29) : Date()
if leapDay != Date()
doy = dayofyear( leapDay )
end
Again, Date() returns this: *0001-01-01*
It works nicely as a "null" date.
Chris
On Tuesday, February 9, 2016 at 11:28:51 PM UTC-5, Michael Landis wrote:
>
> missed a paren above (for the people that are going to past the code into
> a shell and try it out) - something that I am not doing. Still, this is
> closer:
>
> # wishful thinking...
> using Dates;
> leapDay = isleapyear(yr) ? Date(yr,2,29) : nothing
> if ! leapDay
> doy = dayofyear( leapDay )
> ... clean and concise (thought that was the point), but we get
>
> leapDay = isleapyear (yr)? Nullable {Date} (Date (yr, 2:29)): Nullable
> {Date} ()
> if ! isnull( leapDay )
> doy = dayofyear( get(leapDay) )
>
> On Tue, Feb 9, 2016 at 8:22 PM, Michael Landis <[email protected]
> <javascript:>> wrote:
>
>> # wishful thinking...
>> using Dates;
>> leapDay = isleapyear(yr) ? Date(yr,2,29) : nothing
>> if ! leapDay
>> dow = dayofyear( leapDay )
>> ... clean and concise (thought that was the point), but we get
>>
>> leapDay = isleapyear(yr) ? Nullable{Date}( Date(yr,2,29) :
>> Nullable{Date}()
>> if ! isnull( leapDay )
>> dow = dayofyear( get(leapDay) )
>> ...
>>
>> If I am dumb enough to forget to check for a null date, I deserve the
>> exception - the code would be wrong. Making me type two or three times as
>> many characters, obscuring what is actually going on, ... all to eliminate
>> NullPointerExceptions? I have to write exception free code anyway, so all
>> I have 'gained' is a lot of superfluous verbosity. I'm going to side with
>> salience over verbosity every time. The type safe argument just doesn't
>> sell me, sorry.
>>
>
>
