SyntaxError gives you an offset, so you could re-start the decoder if you want that behavior. I'm not convinced that all encoding/json users would want the decoder to skip past syntax errors.

Yes you are right! But it only works on a very inelegant way:
https://play.golang.org/p/XDva7S-Eg28

Agreed that it's inelegant, but is this really a common use case for the json package? I've used the package for many things over the last five years, and never have I needed to skip a syntax error and keep decoding some input.

This seems like a feature request or proposal to me, so it should be backed by some evidence to show that it's needed and useful in many cases. If not, having the user write a bit of extra code for the rare cases where one needs this specific behavior seems fine to me.

Imagine you are reading data from a UDP stream. There it is absolutely possible that a JSON is broken, but I want to read on. The "Decoder" have all information to do that...

Yes it's absolutely a feature request. I could not find a better place for it...