Expose fromCalendarParts

[stephengoldbaum]

Is there a reason not to expose useful functions like fromCalendarParts that can fail with Result? They would be useful.

[justinmimbs]

Hi Stephen,

I agree; it would be useful to expose something for date validation.

There are currently three create-date functions that don't fail on out-of-range values (from[Calendar|Week|Ordinal]Date), and it seems overkill to expose strict versions of all three. I'm guessing a common validation use case is to receive three numbers (year, month, and day) and need to validate them. So exposing fromCalendarParts might be enough.

Alternatively, we could expose a function like isValidYearMonthDay : Int -> Int -> Int -> Bool and keep validation separate from creation.

I know @cmditch wanted to expose some helper functions, I think for the purpose of validating date parts like this.

Any thoughts on a nice API for this based on your use cases?

Thanks,

Justin

[stephengoldbaum]

Hi Justin,

Either of those could work. My thinking with fromCalendarParts is that it already behaves consistently with date libraries from .NET and Java. So partly I want that cross platform consistency and partly it is a more predictable and understandable behavior than rounding out of range values.

I think fromCalendarParts is good from an API perspective.

Thanks,
Stephen

[justinmimbs]

Thanks for the feedback, Stephen. That sounds good to me.

Justin