func datumToJson(datum *p.Datum) ([]byte, error) {
switch datum.GetType() {
case p.Datum_R_NULL:
return json.Marshal(nil)
case p.Datum_R_BOOL:
return json.Marshal(datum.GetRBool())
case p.Datum_R_NUM:
return json.Marshal(datum.GetRNum())
case p.Datum_R_STR:
return json.Marshal(datum.GetRStr())
case p.Datum_R_ARRAY:
items := []string{}
for _, d := range datum.GetRArray() {
item, err := datumToJson(d)
if err != nil {
return nil, err
}
items = append(items, string(item))
}
return []byte("[" + strings.Join(items, ",") + "]"), nil
case p.Datum_R_OBJECT:
pairs := []string{}
for _, assoc := range datum.GetRObject() {
raw_key := assoc.GetKey()
raw_val := assoc.GetVal()
// convert to json form
key, err := json.Marshal(raw_key)
if err != nil {
return nil, err
}
val, err := datumToJson(raw_val)
if err != nil {
return nil, err
}
pairs = append(pairs, string(key)+":"+string(val))
}
return []byte("{" + strings.Join(pairs, ",") + "}"), nil
}
panic("unknown datum type")
}
func isNullDatum(datum *p.Datum) bool {
return datum.GetType() == p.Datum_R_NULL
}