Re: Cross-Platform Windows plus Mac

In comp.sys.mac.programmer.help Ben Artin <macdev@[EMAIL PROTECTED]
> wrote:
> In article <1194537879.688818@[EMAIL PROTECTED]
>,
> Michael Ash <mike@[EMAIL PROTECTED]
> wrote:
> 
>> In comp.sys.mac.programmer.help Ben Artin <macdev@[EMAIL PROTECTED]
> wrote:
>> > Given a language feature that is semantically equivalent in two
languages 
>> > (such as exceptions), not being able to use that feature across the
two 
>> > languages has nothing to do with proper separation and everything to
do 
>> > with running into a limitation of the language bridge and sucking it
up.
>> 
>> You could replace "exceptions" with "objects" in the above and still
have an 
>> accurate statement.
>> 
>> Of course this isn't really a defense of ObjC++, more like a proof that
it 
>> *must* suck, no matter how it's done.
> 
> Well, yes and no. 

You say this, but then you go on to say what appears to be "yes and yes". 
:)

> This line of reasoning ultimately leads you to realize that what you
really need 
> is a common language runtime with well-defined semantics, and then you
need all 
> the languages that you care about to work on top of that runtime. This
is what 
> Microsoft did with CLR, and this is increasingly the direction that
Apple is 
> going in by bridging the Obj-C runtime to Python, Perl, Ruby, etc.
> 
> Then you realize that C++ can't work on top of any sane runtime, at
which point, 
> if you are Microsoft, you invent a modified version of C++ that can or,
if you 
> are me, you realize that you are better off using a language (such as
Python) 
> that works on top of a sane runtime.

In other words, the only way for ObjC++ not to suck would be to do things 
that result in no longer having C++ anymore. Ergo, ObjC++ must suck.

However, I wonder if this is really true. So much of C++ is in the 
compiler by its very nature. I imagine you could host C++ on top of a more

dynamic runtime, and just have C++ ignore most of the dynamism. Virtual 
function calls could be replaced with true dynamic dispatch, for example. 
Static function calls could just be normal function calls, or they could 
end up doing dynamic dispatch on some suitably uniqued name. Stack objects

could be replaced with heap objects with automatic refcounting or GC. Then

you expose all the C++ functions as methods in the runtime and other 
languages would then be allowed to use duck typing and all the rest.

Of course a major consequence of this would be to suddenly make C++ 
*slower* than the others, due to all the extra indirection. That might be 
enough to qualify as "suck", but I'm not sure.

This is all just a thought experiment anyway. I personally have no need 
for such a thing, and I agree with you that you're better off switching 
languages if it comes to that.

-- 
Michael Ash
Rogue Amoeba Software