Fix repr on Period Types, and DateTime, Date

[fchorney]

Jumping off of this previous PR #30200

It seems the Period types face a similar issue. Year, Month, Week, Day, Hour, Minute, Second, Millisecond, Microsecond, and Nanosecond

julia> using Dates

julia> show(Hour(1))
1 hour

Realistically this should show the equivalent repr type output. Hour(1)

I also noticed that the previous PR that is referenced in this one prints out "DateTime" or "Date" regardless of how Dates was imported. import vs using.

When using import, you would expect

julia> import Dates

julia> show(Dates.Hour(1))
Dates.Hour(1)

and with using, you would expect

julia> using Dates

julia> show(Hour(1))
Hour(1)

[JeffBezanson]

Nice, thank you (and welcome)!

Not directly related, but I also notice Dates defines a few methods for Base.string and then defines print(io, x) = print(io, string(x)), which is redundant. In fact it should only define the print methods, then you get string for free.

[JeffBezanson]

This isn't quite right --- 1 day should still be printed in the REPL, but repr should give Dates.Day(1). The BitPeriod type can be removed, and instead the current show method should be a method show(io::IO, ::MIME"text/plain", p::Period), and your new method might not be necessary since the fallback 2-argument show will probably print Dates.Day(1).

[fchorney]

Right, I see what you're saying. I think my latest change should satisfy those requirements, while also satisfying 1 day being shown in outputs such as in a dataframe.

[omus]

Nice work 👍

[fchorney]

Looks like the macOS build failed trying to pull a package

Got exception outside of a @test
  failed to clone from https://github.com/JuliaIO/JSON.jl.git, error: GitError(Code:ERROR, Class:Net, curl error: Could not resolve host: github.com)

[omus]

@JeffBezanson does this look good to you?