39 lines
817 B
Go
39 lines
817 B
Go
|
package nul
|
|||
|
|
|
|||
|
|
import (
|
|||
|
|
"fmt"
|
|||
|
|
"encoding/json"
|
|||
|
|
)
|
|||
|
|
|
|||
|
|
var _ json.Unmarshaler = new(Nullable[bool])
|
|||
|
|
var _ json.Unmarshaler = new(Nullable[string])
|
|||
|
|
|
|||
|
|
// UnmarshalJSON makes it so json.Unmarshaler is implemented.
|
|||
|
|
func (receiver *Nullable[T]) UnmarshalJSON(data []byte) error {
|
|||
|
|
switch interface{}(receiver.value).(type) {
|
|||
|
|
case bool, string:
|
|||
|
|
// these are OK.
|
|||
|
|
default:
|
|||
|
|
return fmt.Errorf("cannot unmarshal into something of type %T from JSON because parameterized type is ‘%T’ rather than ‘bool’ or ‘string’", receiver, receiver.value)
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
if 4 == len(data) && 'n' == data[0] && 'u' == data[1] && 'l' == data[2] && 'l' == data[3] {
|
|||
|
|
*receiver = Null[T]()
|
|||
|
|
return nil
|
|||
|
|
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
{
|
|||
|
|
var dst T
|
|||
|
|
|
|||
|
|
err := json.Unmarshal(data, &dst)
|
|||
|
|
if nil != err {
|
|||
|
|
return err
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
*receiver = Something(dst)
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
return nil
|
|||
|
|
}
|