[Haskell-cafe] Re: Versioning

[Robert Dockins]

On Dec 20, 2006, at 2:37 PM, Joachim Durchholz wrote:

> Ross Paterson schrieb:
>>> It might be not feasible though. The papers mention that you  
>>> can't serialize (well, actually unserialize) function values with  
>>> it. For the envisioned update-through-marshalling process, this  
>>> would prevent me from ever using function values in data that  
>>> needs to be persistent, and that's quite a harsh restriction.
>> That's hard to avoid, unless you have a data representation of the
>> functions you're interested in.
>
> I could encode functions by their name. I don't think that would  
> scale to a large application with multiple developers, but it's not  
> this kind of project anyway.
> I'd be reluctant to accept that way if it means adding boilerplate  
> code for every function that might ever be serialized. Since I'm  
> planning to serialize an entire application, I fear that I'd need  
> that boilerplate code for 90% of all functions, so even a single  
> line of boilerplate might be too much.

Let me just say here that what you are attempting to do sounds very  
difficult.  As I understand, you want to be able to serialize an  
entire application at some (predetermined / arbitrary?) point, change  
some of its code and/or data structures, de-serialize and run the  
thing afterwards.  Doing something like this without explicit  
language support is going to be hard, especially in a fairly static  
language like Haskell.

I would think Smalltalk, Erlang, or something from the Lisp/Scheme  
family would be more suitable for this sort of work (caveat, I have  
little experience with any of these languages).  Also, take a look  
here (http://lambda-the-ultimate.org/node/526) for some related  
discussion.



> Regards,
> Jo


Rob Dockins

Speak softly and drive a Sherman tank.
Laugh hard; it's a long way to the bank.
           -- TMBG