initial commits

temporal_unmarshaljson.go

@@ -0,0 +1,37 @@
+package tmp
+
+import (
+	"encoding/json"
+
+	"sourcecode.social/reiver/go-erorr"
+)
+
+var _ json.Unmarshaler = new(Temporal[bool])
+var _ json.Unmarshaler = new(Temporal[string])
+
+// UnmarshalJSON makes it so json.Unmarshaler is implemented.
+func (receiver *Temporal[T]) UnmarshalJSON(data []byte) error {
+	switch interface{}(receiver.value).(type) {
+	case bool, string,json.Unmarshaler:
+		if 4 == len(data) && 'n' == data[0] && 'u' == data[1] && 'l' == data[2] && 'l' == data[3] {
+			return erorr.Errorf("tmp: cannot unmarshal a JSON `null` into something of type %T", receiver.value)
+		}
+
+		// these are OK.
+	default:
+		return erorr.Errorf("tmp: cannot unmarshal into something of type %T from JSON because parameterized type is ‘%T’ rather than ‘bool’, ‘string’, or ‘json.Unmarshaler’", receiver, receiver.value)
+	}
+
+	{
+		var dst T
+
+		err := json.Unmarshal(data, &dst)
+		if nil != err {
+			return err
+		}
+
+		*receiver = Permanent(dst)
+	}
+
+	return nil
+}