Scratch my previous answer - it's undocumented, but it IS possible, I found it by reading the compiler code. Bah.
go.tag
This piece of thrift code:
struct foo {
1: string bar (go.tag = "json:\"baz\" yo:\"dawg\""),
2: string bang
}
Generates the following Go code:
type Foo struct {
Bar string `thrift:"bar,1" json:"baz" yo:"dawg"`
Bang string `thrift:"bang,2" json:"bang"`
}