That's impossible because godoc cannot possibly know about all interfaces that is in all the Go code out there.
Re:Interfaces in Go make it hard to navigate code
by georgemcbay on Monday May 27, 2013 @07:29AM
(#5774251)
It can know about all the interfaces in your current $GOROOT and $GOPATH, which is the set of code you'd be interested in anyway.
Re:Interfaces in Go make it hard to navigate code
by DanWaterworth on Wednesday May 29, 2013 @02:14AM
(#5784897)
Installing packages is now quadratic time. Go doesn't scale.
Re:Interfaces in Go make it hard to navigate code
by galaktor on Monday May 27, 2013 @05:55AM
(#5774064)
The doc could only display implemented interfaces that it knows about, so when you generate the docs they show which interfaces a type implements from within that particular library (and it's dependencies, since go takes it all as source code). You wouldn't, however, know which interfaces from github.com/foo are implemented by types of bitbucket.org/bar unless their docs were somehow generated together.
The lack of clearly defined interfaces in the documentation was one of the big turn offs when I tried go a while back.