Re: 'withing' problem [code generation]

["Matthew Heaney" <mheaney@on2.com>]

"Stephen Leake" <stephen.a.leake.1@gsfc.nasa.gov> wrote in message
news:u3d3aeavn.fsf@gsfc.nasa.gov...
> The point here is that extending Ada with "with type" allows some
> "circularities" to be directly represented, without any user or tool
> interaction.

The circularity can already be directly represented, by simply
forward-declaring one of the types.  A language change is only necessary in
order to change the syntax of the forward declaration, and to remove the
(small) run-time penalty.

(I should also add, "in order to interface to IDL and Java." But in the
latter case, still more language changes would be required, e.g. interface
types.)

>For example, assume your UML model has the Doctor -> Patient
>circularity. The first time you generate code, it may decide to break
>the circularity by using a forward declaration for Doctor. Now you
>tweak the model a bit, and it decides to forward declare Patient. Not
>a Good Thing!

I don't understand this argument.  If you're using a code generator, then
what difference does it make what code is generated?  If you care that much,
then why don't you just write the code manually?