Feature request: Unmarshaling

[milkpirate]

I'd like to unmarchal a YAML config into a struct holding a MIME field.

type Cfg struct {
	Mime           mimetype.MIME  `yaml:"mime" json:"mime" default:"application/json"`
}

Doing so produces:

yaml: unmarshal errors:
	  line 1: cannot unmarshal !!str `applica...` into mimetype.MIME

panic: json: cannot unmarshal string into Go struct field Cfg.mime of type mimetype.MIME

Could you add the corresponding unmarchaling function?

[gabriel-vasile]

I feel that implementing this will create a whole deal of complications because:

• multitude of formats
• both marshal and unmarshal must be implemented because users will expect unmarshal(marshal(m)) == m
• users might expect functions like Extend to work. This goes into a grey area because Extend alters global state of the library...

Using existing API seems reasonable to me:

type Cfg struct {
	Mime  string  `yaml:"mime" json:"mime" default:"application/json"`
}

m := mimetype.Lookup(cfg.Mime) // also gives the opportunity to check m == nil in case cfg.Mime is not supported 

I will leave this issue open for now. If anyone thinks implementing this is useful, please upvote it.