Candied Yaml doesn't support merge.

manifest.yml

---
services:
- acceptance-db
env:
  RAILS_ENV: acceptance

application-types:
  web: &WEB
    mem: 2G
    disk: 2G

applications:
- 
  name: blue
  <<: *WEB

test.go

package main

import (
	"fmt"
	"os"
	"path/filepath"

	"github.com/cloudfoundry-incubator/candiedyaml"
	"github.com/cloudfoundry/cli/generic"
)

func parseManifest(path string) (yamlMap generic.Map) {
	file, err := os.Open(filepath.Clean(path))
	if err != nil {
		fmt.Println("Could not open")
		return
	}
	defer file.Close()

	decoder := candiedyaml.NewDecoder(file)
	yamlMap = generic.NewMap()
	err = decoder.Decode(yamlMap)
	if err != nil {
		return
	}

	if !generic.IsMappable(yamlMap) {
		fmt.Println("Invalid manifest - not a map")
		return
	}

	return
}

func main() {
	mapp := parseManifest("./manifest.yml")
	fmt.Println(mapp)
}

○ → go run test.go
map[services:[acceptance-db] env:map[RAILS_ENV:acceptance] application-types:map[web:map[mem:2G disk:2G]] applications:[map[name:blue <<:map[disk:2G mem:2G]]]]