Am 23.08.2011, 19:42 Uhr, schrieb jdrewsen <jdrew...@nospam.com>:
Den 23-08-2011 17:03, Jacob Carlborg skrev:
On 2011-08-23 16:38, Andrei Alexandrescu wrote:
On 8/23/11 12:55 AM, Jacob Carlborg wrote:
On 2011-08-23 08:52, Andrei Alexandrescu wrote:
On 8/22/11 11:30 PM, Jacob Carlborg wrote:
Ok, then I just change "register" to a static method.
A static method of whom?
Andrei
Well, "register" currently an instance method of Serializer so I would
change it to be a static method of Serializer.
I think the ability of a class to be serialized would be independent of
the notion of a serializer. To me, "this class is serializable" really
means "this class has metadata associated with it that allows
interested
parties to serialize it". But perhaps this is splitting hairs.
Andrei
You don't want to have it in the class and don't want it in the
serializer. I mean, it needs to be stored somewhere and I thought that a
static method in Serializer would better than a completely global
function.
Are you thinking about having another serialization library that can use
this information as well? I'm not sure if that's good idea, different
serialization implementations might need to do very different things
with the information.
It could be used for network transmissions. Correct me if I'm wrong but
Orange serializes the entire object. When sending things over the
network or when saving something to disk for that matter you most likely
are only interested in serializing some of the fields of an object. I
really think it would be nice to declaratively mark fields as
serializable for certain purposes e.g.:
class Foo {
int a; // Send over network and saved to file
int b; // Saved to file
ubyte[] cache; // not to be serialized
}
mixin(serialize!(Network, Foo, a);
mixin(serialize!(File, Foo, a);
mixin(serialize!(File, Foo, b);
// but still support not specifying each field
class Bar { int a; }
mixin(serialize!(File, Bar));
Another way would be to just declare a class as serializable and then
for each serialization type (ie. Network, File) declare that they should
skip a field. Actually I think I better like this approach since it
would allow decoupling of serialization type and the declaration of
serializability.
/Jonas
These are good points Jonas. It's a good idea to read up on
http://en.wikipedia.org/wiki/Serialization
I used Java for a while and I they have their reasons to require a
'tag'/'annotation'/'interface' on serializable classes.
Java's choice to not make serializable a default is explained in short
like this:
- structures like threads or files cannot maintain their semantics when
serialized
- classes and libraries change over time, this adds extra work for the
maintanance of serializable classes
- serialization means externalization of private attributes, even passwords
.NET adds the option to mark newly added fields as OptionalField, so a
previously serialized instance can be loaded without error. NonSerialized
marks a field as not serializable which is what Jonas mentioned. Like Java
they work with interfaces to declare methods called after deserialization,
so the 'cache' in the above example can be reinitialized correctly.
