json RawMessage and interface{}

[Johann Höchtl]

According to the docs, if the Marshaller of json hits a json.RawMessage struct member, it won't apply encoding heurisitics, that's at least my understanding. Following this thread it works:
http://play.golang.org/p/b8fzGMxrMC

But what if the struct member is of type interface{}, according to the documentation, "Interface values encode as the value contained in the interface." So I thought that member Data of a struct defined as

type S struct {
    Data interface{}
}

and assigned like that

Data: json.RawMessage([]byte(`{"Blah":"42"}`))

it will still end up base64 encoded.

[Johann Höchtl]

As it turns out I have indeed been hit by the json RawMessage pointer receiver inconvenience.

This doesnt' work: http://play.golang.org/p/HmvqdQWLLm
This works: http://play.golang.org/p/6FgwQEWj69

[aro...@gmail.com]

For the record, I vote that this is considered a bug and be fixed in go 1.x.  I can't see any reasonable usage that exploits the non-pointer receiver functionality intentionally, and it's VASTLY more likely to be a recurring source of bugs.

- Augusto

[Benjamin Measures]

On Thursday, 27 February 2014 19:47:20 UTC, aro...@gmail.com wrote:

For the record, I vote that this is considered a bug and be fixed in go 1.x.  I can't see any reasonable usage that exploits the non-pointer receiver functionality intentionally, and it's VASTLY more likely to be a recurring source of bugs.

That MarshalJSON has a pointer receiver is consistent with UnmarshalJSON. This is important.

[Matt Harden]

Why? What's important about it?