yaml

config.WithOptions(config.ParseEnv)

// add yaml decoder
// only add decoder
// config.SetDecoder(config.Yaml, Decoder)
// Or
config.AddDriver(Driver)

err := config.LoadFiles("testdata/yml_other.yml")
if err != nil {
	panic(err)
}

// load from string
config.LoadSources(config.Yaml, []byte(yamlStr))

fmt.Print("get config example:\n")

name, ok := config.String("name")
fmt.Printf("get string\n - ok: %v, val: %v\n", ok, name)

arr1, ok := config.Strings("arr1")
fmt.Printf("get array\n - ok: %v, val: %#v\n", ok, arr1)

val0, ok := config.String("arr1.0")
fmt.Printf("get sub-value by path 'arr.index'\n - ok: %v, val: %#v\n", ok, val0)

map1, ok := config.StringMap("map1")
fmt.Printf("get map\n - ok: %v, val: %#v\n", ok, map1)

val0, ok = config.String("map1.key")
fmt.Printf("get sub-value by path 'map.key'\n - ok: %v, val: %#v\n", ok, val0)

// can parse env name(ParseEnv: true)
fmt.Printf("get env 'envKey' val: %s\n", config.DefString("envKey", ""))
fmt.Printf("get env 'envKey1' val: %s\n", config.DefString("envKey1", ""))

// Out:
// get config example:
// get string
// - ok: true, val: app2
// get array
// - ok: true, val: []string{"val1", "val21"}
// get sub-value by path 'arr.index'
// - ok: true, val: "val1"
// get map
// ok: true, val: map[string]string{"key":"val2", "key2":"val20"}
// get sub-value by path 'map.key'
// - ok: true, val: "val2"
// get env 'envKey' val: /bin/zsh
// get env 'envKey1' val: defValue

// Notice: before dump please set driver encoder
config.SetEncoder(config.Yaml, Encoder)

buf := new(bytes.Buffer)
_, err := config.DumpTo(buf, config.Yaml)
if err != nil {
	panic(err)
}

fmt.Printf("export config:\n%s", buf.String())

// Out:
// arr1:
// 	- val1
// 	- val21
// baseKey: value2
// debug: false
// ... ...