Re: [boost] [serialization docs] Ping?

From: Simon Buchan (simon_at_[hidden])
Date: 2005-09-27 19:34:50

Jonathan Turkanis wrote:
> Simon Buchan wrote:
> 
>>Jonathan Turkanis wrote:
> 
> 
>>>Note that I'm not criticising the standard (although it certainly
>>>has some problems with lack of precision). It would be nice to have
>>>a truly formal specification, but in the case of C++ it's probably
>>>not realistic.
>>>
>>
>>I do think it's possible
> 
> 
> I said 'realistic'
> 
I should have /emphasised/ it, sorry.
> 
>>(If it wasn't, we wouldn't be able to write
>>compilers for it!),
> 
> 
> That's like saying: Of course it must be possible to provide a formal semantics
> for English -- otherwise I'd never be able to understand the instructiosn that
> come with my coffee maker :-)
> 
Can you? If so, English (or more precisely, the subset used in the 
instructions) can be formally defined (in fact, you can find programs 
that do).  The problem with natural languages is that they have a symbol 
table with trillions of entries, and that table is dynamicly generated 
based on the situation the compiler (ie, you) is in.
> 
>>but remember the standard has basicly grown out of
>>rewordings from the days of C (which did likewise back to B, etc...)
>>I think a formal, but human-readable, grammar, kind of like EBNF for
>>semantics, would be useful here.
> 
> 
> It would be very useful (except I'm not sure what you mean by "kind of like EBNF
> for semantics")
> 
Think algebra for syntax.  That's EBNF.  I don't know of any generalised 
definition of semantics (Turing machines don't count, 'cause they arn't 
human-readable (even the definition of Turing machines arn't!), and 
Lambda Calculus isn't general enough.) that would be useful, but feel 
free to correct me.