Determine a Value's Definitions

[pahansen95]

How can I retrieve what Definitions a cue.Value implements when using Cue's Go API?

Given:

-- specs.cue --

#LocalTarget: {
  id: string
}

#PortalTarget: {
  id: string
  address: string | *"device-portal.example.com"
  token: string
}

#SshTarget: {
  id: string
  address: string | *"localhost:22"
  user: string
  privateKey: string
}

#Task: {
  exec: string | *"sh"
  argv: [string]
  env: [string]: string
}

-- config.cue --

{
  target: #SshTarget & {
    id: "foobar"
    address: "192.168.0.1:22"
    user: "pahansen95"
    privateKey: "$HOME/.ssh/id_rsa"
  }
  task: #Task & {
    argv: ["echo", "$WORD"]
    env: {
      "WORD": "Hello World!"
    }
  }
  meta: "The answer is 42."
}

I'm trying to do the following:

/* -- main.go -- */

// imports

func contains(set []string, item string) bool {
  // ...
}

func exec(task *cue.Value) error {
  // ...
}

func getdefs(v *cue.Value) ([]string, error){
  defs := make([]string, 0)
  /* 
 
    How do I get the Definitions a Value Implements (if any)? 

  */
  return defs, nil
}

func main() {
  noOpts := []cue.Options{}...
  confBytes, _ := os.ReadFile("./config.cue")

  cueCtx := cuecontext.New()
  cueVal := cue.CompileBytes(confBytes, noOpts...)
  
  fieldIter, _ := cueVal.Fields(noOpts...)
  items := map[string]*cue.Value
  for {
    if fieldIter.Selector().String() == "target" {
      items["target"] = fieldIter.Value()
    }
    if fieldIter.Selector().String() == "task" {
      items["task"] = fieldIter.Value()
    }
   // ignore all other Selectors
    if !iter.Next(){
      break
    }
  }

  /*
    The Important Bit
  */
  structDefs, _ := getdefs(items["target"])
  if contains(structDefs, "SshTarget") {
    // Open SSH connection
  } // Else don't do anything special
  
  err := exec(items["task"])
  if err != nil {
    // Log Error
    os.Exit(1)
  }
}

In this example what I'm trying to do is figure out what type of target I'm executing against. I assumed I would be able to determine that via the Definition of the struct. My workaround currently is to embed the "Classification" into the struct as a separate field.

How would you approach this in an idiomatic way using Cue's design?