Re: Here's a gui app builder

[Marcus G. Daniels]

>>>>> "PJ" == Paul E Johnson <address@hidden> writes:

PJ> Using this does not require any separate layer, COM, etc, which I
PJ> think is a little comforting.

If you are interested in having live objects running and probing them,
the lack of a metadata system for interfaces should not comfort you.
Having a compiler between you and manipulation of a model component (a
code generation step), is a much worse kind of opacity, IMO. 

PJ> Maybe I have to learn c++ and translate some base Swarm libraries
PJ> into that format in order to talk to a program like this.

COM gives you C++. You'd run "xpidl -m header swarmIZoomRaster.idl",
which will create headers that you could import into a package like
this.

PJ> If Swarm classes could "reflect" their variables and methods out
PJ> to a gui like WideStudio, it could be really fun.

It tends to be hard to do that in C++ because there are not portable
ways to do type interrogation of live objects.  So you need to use
conventions to ask objects about what is in them.  That's what COM is,
in a nutshell.  COM by itself is not a "layer".  For example, if you
run a C++ COM application in a debugger and step through method calls,
there's no sense in which you are in "other stuff that isn't mine and
I don't understand [why are they doing this to me], etc".  Of course you
may step into a system library or a third-party library, but that has
nothing to with COM.

With Swarm, there is a COM "layer", and that is because Swarm was
not written with COM (or Java) in mind.  So it's necessary to inform the
metadata/runtime systems with information about Swarm and to connect
them together.  It turns out that Objective C is a pretty good language
for this kind of integration because it has its own reflection features
and is close to C, which is compatible with everything. 

I'll have to build WideStudio to see how they aim to support
reflection.


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