Encodes elm dates as UtcIso strings.

[alex-wellbelove]

This is parseable in Haskell with aeson, for instance. https://github.com/TriviumRealEstate/excelsior/pull/480.

[ChickenProp]

Note that this will make it impossible to send a full datetime without another PR to this repo. We also won't be able to send this upstream. And I'm not sure, but it looks like sending a date to Elm would still require it to be a datetime.

These may well be good tradeoffs to make right now, but they're worth noting.

(The solution I'm thinking of is having two separate ElmPrimitive cases, one for datetimes and one for date-onlys. Both would serialize to Date, but the encoding and decoding functions for them would be different. But that would take considerably longer than this.)

---

http://package.elm-lang.org/packages/justinmimbs/elm-date-extra/latest/Date-Extra#toUtcIsoString says the function you're using formats dates with a timestamp? Currently we're using Exts.Date.toRFC3339 for this.

[alex-wellbelove]

What do you mean by

Note that this will make it impossible to send a full datetime without another PR to this repo.
?

Agree re the separate serializations, but for now it's enough to do utctDay on the haskell side etc.

[ChickenProp]

I misunderstood the point of this PR - I thought it was making it so that an Elm Date could be serialized to a haskell Day, but in fact it's just turning an Elm Date into a Haskell UTCTime, which the library really ought to provide out of the box. All of my concerns were misplaced.

[alex-wellbelove]

krisajenkins/elm-export#38

[trippingtarballs]

Blocks https://github.com/TriviumRealEstate/excelsior/pull/481