[antlr-interest] "finally" blocks
alan at engrm.com
Mon Jan 17 22:25:16 PST 2005
* Paul J. Lucas <pauljlucas at mac.com> [2005-01-18 01:13]:
> On Tue, 18 Jan 2005, Alan Gutierrez wrote:
> > Paul J Lucas wrote:
> > > I don't have Bjarne's book in front of me, but he talks about
> > > the general concept is about resource aquisition and release
> > > (which is mostly what "finally" in Java is used for, e.g., open
> > > a file, make sure it's closed, etc.).
> > RAII. Resource Allocation is Initialization. Modern C++
> > relies heavily on the use of destructors to restore state
> > when the stack is unwound.
> Yes, I know.
> > The question as to whether it is general, I'm not sure I
> > understand. If you're wondering whether it is a generally
> > accepted practice in C++, the answer is yes.
> I wasn't asking. I think you're misquoting. Terence was the
> one who was asking.
Yes. I know. And if Terrence was asking if reliance of
destructors is prevelent in C++, in leiu of finally, I'm saying,
the answer is yes.
> > > In ANTLR for C++, you don't need "finally" at all because if
> > > the user wants the functionality, s/he can simply do what I
> > > did, i.e., create a variable having a destructor.
> > And a decent C++ type is built around RAII and a destrcutor that
> > does the right thing.
> Yes, I agree, but there's no such standard type wrappers for
> built-in types which is exactly what my example was for.
> The lone standard such wrapper is auto_ptr<T>.
Boost has a number of such wrappers. I also consider the
std::string, std::list, std::vector to be RAII wappers.
> > You could still have that finally block for C++ ...
> How, exactly? if I have:
> > Finally exists in C++ ...
> No it doesn't.
My mistake. I'll go back to saying, for C++, forget about it.
Alan Gutierrez - alan at engrm.com
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