Use rustler's builtin serde support

[filmor]

No description provided.

[benhaney]

Oh awesome, I didn't know Rustler had integrated Serde support now! Although it does look like it inherited the weird behavior of serde_rustler that forced me fork it, where the :ok and :error atoms get serialized as the strings "Ok" and "Err", inconsistent with all other atoms (see issue #6). Some other minor issues are that this probably breaks Decimal encoding support (because I manually implemented that in my serde_rustler fork) though I don't have a test for it apparently, and changes some error tuple text (which I care much less about and mostly just needs updated tests).

I'd love to use Rustler's built-in Serde, but it would need to match Jsonrs's existing behavior so we aren't regressing a bunch of bugs and breaking compatibility.

[filmor]

Thank you, that is exactly the input I was looking for. Would you mind opening an issue for this on the Rustler repo?

[praveenperera]

@filmor that would be a nice change, then I could get rid of these lines in fast_rss

https://github.com/avencera/fast_rss/blob/6fa58824398c6119ced024377e31be54c4fa28c0/lib/fast_rss.ex#L67

[benhaney]

The ok/error serialization is fixed in Rustler (rusterlium/rustler#639), so now this PR is just waiting on Rustler to add the ability to register custom struct deserializers.