JSON元帅的Stringer等效项

I can implement Stringer to specify how fmt.Print() will write my custom type as a string. Is there an equivalent for json marshal?

I want to store unique values in go and represent it as a slice in json. Using a slice in go isn't optimal for this. This O(n) insert seems unnecessary - a binary tree or map would be faster, specially since I'm keeping the list sorted at all times.

Yes, json.Marshaler and json.Unmarshaler.

Implementing MarshalJSON and UnmarshalJSON will give you what you want.