[question] Why can't Encoder check and call fmt.Stringer.String() on element automatically?

[howellzhu]

Why can't Encoder directly determine whether an element implements an interface (such as fmt.Stringer or encoding.TextMarshaler) and actively call its interface to implement Encode()?

After all, Decode already does that (using encoding.TextUnmrshaler interface).

[jaitaiwan]

I can look at this again, but from my understanding, go doesn't have a specific way to check if a type implements an interface. We'd have to do reflection and see if a method with a particular name existed. I'm not sure what the benefit of doing this would actually be.