Embedding a map in a struct

[Dustin Norlander]

Hi,

I've searched all over and can't find the answer to this.

I have a struct I would like to extend a map.  Based on what I've read it should look like :

type MyMap struct {

    *map[string]interface{}

    SomeField string

}

or possibly this:

type MyMap map[string]interface{} {

    SomeField string

}

Neither work.  Is there a way to do this?

thanks much,

Dustin

[bryanturley]

You can't extend map, you can use it in a struct and use the struct as a non built-in map though.

http://play.golang.org/p/Rj-JrHKdAf

don't use interface {} if you can use something specific

[Archos]

There are several ways:

http://play.golang.org/p/sZqVHPGdNl

[bryanturley]

On Wednesday, November 28, 2012 5:27:48 PM UTC-6, Archos wrote:

There are several ways:

http://play.golang.org/p/sZqVHPGdNl

meh, except that isn't really extending it

http://play.golang.org/p/ozwnBJm26p   <--- he probably wants the doesn't work example

[Archos]

 The same for your example:

http://play.golang.org/p/Bl2O3FbNoV

[Dustin Norlander]

Thanks guys.  Looks like what I wanted just isn't possible.  good to know.

-Dustin

[bryanturley]

Indeed, that is why I defined Get() and Set() and showed and example of their use.

[Archos]

 Of course, and I'm sure that the OP would know add a methods to a structs already implemented like in mi examples.

[Kevin Gillette]

What you're suggesting is embedding an unnamed type. Since brace, bracket, and asterisk characters are not valid identifier characters, you couldn't access the underlying field anyway --

  m := MyMap{}

  m.*map[string]interface{}["something"]

That would be a syntax error.

You can embed any unnamed type:

type underlyingmap map[string]interface{}

type MyMap struct {

  underlyingmap

  SomeField string

}

m := MyMap{}

m.underlyingmap["something"]

The above should work.