compiler support added for precise GC

[Alex Rønne Petersen]

On 17-04-2012 10:13, Walter Bright wrote:
> On 4/17/2012 1:10 AM, Walter Bright wrote:
>> On 4/16/2012 11:50 PM, Jacob Carlborg wrote:
>>> On 2012-04-17 08:33, Walter Bright wrote:
>>>> On 4/16/2012 11:26 PM, Jacob Carlborg wrote:
>>>>> Then it won't be possible to serialize third party types if they don't
>>>>> implements ISerializable. In this case, this solution is no better
>>>>> then manually
>>>>> registering types. Actually it's worse, since I can manually register
>>>>> third
>>>>> party types.
>>>>
>>>> I'm not so sure in D that you can serialize arbitrary types without
>>>> them
>>>> designed to be serializable. For example, what will you do with unions?
>>>> Pointers to global data?
>>>
>>> Not all types are serializable of course.
>>
>> How would you know if they are or aren't, when dynamically loading stuff?
>
> Essentially, I'm concerned with a vast amount of data being generated
> for every type and inserted into the executables (which are already
> large). Even worse, I'm concerned that such a feature will not "just
> work" when one wants to serialize a class that wasn't designed to be
> serialized, and it'll come off as a crappy half-assed buggy misfeature.

Would turning on global reflection data generation with a compiler 
switch be reasonable? Then when libraries query for reflection 
information, they just have to check whether it's actually there (and if 
not, most likely error).

Anyway, I don't think reflection has the potential to be a misfeature; 
that's stretching it. Redundancy can certainly be incurred, but with a 
switch to enable reflection, it would only happen when the user actually 
wants it to.

As for the just works factor - if the serialization library is designed 
well enough (which I'm confident Jacob's library either is can be made 
to be), it isn't really a problem. Serializing a graph of objects is 
pretty standard (see e.g. .NET binary serialization).

Even better, the library could just error out (instead of producing 
garbage) when it discovers that it can't serialize a type in any 
sensible fashion.

-- 
- Alex