// otherwise any punctuation chars are allowed
			// in a tag name.
		case !unicode.IsLetter(c) && !unicode.IsDigit(c):
			return false
		}
	}
	return true
}

func typeByIndex(t reflect.Type, index []int) reflect.Type {
	for _, i := range index {
		if t.Kind() == reflect.Pointer {
			t = t.Elem()
		}
		t = t.Field(i).Type
	}
	return t
}