I was wondering if there are any open source compilers out there to
translate the C++/Java/C#-like object model to C. Thanks,

David

dvanguard@gmail.com wrote:
> I was wondering if there are any open source compilers out there to
> translate the C++/Java/C#-like object model to C. Thanks,

An early C++ "compiler" perhaps?

As I understand it, C++ was initially precompiled to C source.

Mark Bluemel wrote:
> dvanguard@gmail.com wrote:
>> I was wondering if there are any open source compilers out there to
>> translate the C++/Java/C#-like object model to C. Thanks,
>
> An early C++ "compiler" perhaps?
>
> As I understand it, C++ was initially precompiled to C source.
'cfront' might be what you're looking for, although I guess the generatted
code would be pretty illegibel to humans.

Bye, Jojo

On Jan 31, 11:32 am, Mark Bluemel <mark_blue...@pobox.com> wrote:
> dvangu...@gmail.com wrote:
> > I was wondering if there are any open source compilers out there to
> > translate the C++/Java/C#-like object model to C. Thanks,
>
> An early C++ "compiler" perhaps?
>
> As I understand it, C++ was initially precompiled to C source.

yep cfront did it (the original compiler for AT&T). I think comeau c++
compiler still does that: from C++ sources it generates C code
http://www.comeaucomputing.com/.

On Jan 31, 8:20am, dvangu...@gmail.com wrote:
> I was wondering if there are any open source compilers out there to
> translate the C++/Java/C#-like object model to C. Thanks,

Here you go:
http://www.softwarepreservation.org/.../release_3.0.3

Don't imagine that reading the C output will be enjoyable.

:

> I was wondering if there are any open source compilers out there to
> translate the C++/Java/C#-like object model to C. Thanks,
>
> David


Hidden pointers is what OO is all about for the most part.

The following in C++:


class Circle {
public:

double radius;

virtual double GetArea(void)
{
3.14 * radius * radius;
}

};



is implemented as:



typedef struct VTable_Circle {
double (*GetArea)(Circle*);
} VTable_Circle;

typedef struct Circle {
VTable_Circle const *vtable;

double radius;
} Circle;

double GetArea(Circle *const this)
{
return 3.14 * this->radius * this->radius;
}

VTable_Circle vtable_circle = { GetArea };

void ConstructCircle(Circle *const p)
{
p->vtable = vtable_circle;
}


--
Tomás Ó hÉilidhe

dvanguard@gmail.com wrote:
>I was wondering if there are any open source compilers out there to
>translate the C++/Java/C#-like object model to C. Thanks,

Check the Portable Object Compiler for an Objective-C to C translator:

http://users.pandora.be/stes/compiler.html


Roberto Waltman

[ Please reply to the group,
return address is invalid ]

"Tomás Ó hÉilidhe" <toe@lavabit.com> wrote in message
news:Xns9A36E9FB8AD8toelavabitcom@194.125.133.14.. .
> :
>
>> I was wondering if there are any open source compilers out there to
>> translate the C++/Java/C#-like object model to C. Thanks,
>>
>> David
>
>
> Hidden pointers is what OO is all about for the most part.
>
> The following in C++:
>
[...]
>
> is implemented as:
>
>
>
> typedef struct VTable_Circle {
> double (*GetArea)(Circle*);
> } VTable_Circle;
>
> typedef struct Circle {
> VTable_Circle const *vtable;
>
> double radius;
> } Circle;
>
> double GetArea(Circle *const this)
> {
> return 3.14 * this->radius * this->radius;
> }
>
> VTable_Circle vtable_circle = { GetArea };
>
> void ConstructCircle(Circle *const p)
> {
> p->vtable = vtable_circle;
> }

FWIW, you can use some macros to implement the interface so you don't have
to write code like:


Circle c;
ConstructCircle(&c);
c.vtable->GetArea(&c);




Something like:

#define Circle_GetArea(mp_this) ( \
(mp_this)->vtable->GetArea((mp_this)) \
)




Now you can do:

Circle c;
ConstructCircle(&c);
Circle_GetArea(&c);




Also, if you pick some standard function names in the vtable, you could do
some abstract interface stuff... Something like:


typedef struct VTable_Circle {
void (*Object_Destroy) (Circle*);
double (*GetArea)(Circle*);
} VTable_Circle;


#define Object_Destroy(mp_this) ( \
(mp_this)->vtable->Object_Destroy((mp_this)) \
)



and write:

Circle c;
ConstructCircle(&c);
Circle_GetArea(&c);
Object_Destroy(&c);



The Object_Destroy function will work for any object which follows the
"standard" vtable naming convention.



Here is a more complete example:

http://groups.google.com/group/comp....106926ba5db19f




IMHO, it makes things "cleaner"... And in some respects, I like it better
than C++...



;^)