Re: Woo hoo ... a whole new set of compiler headaches!! - Mailing list pgsql-hackers

> -----Original Message-----
> From: pgsql-hackers-owner@postgresql.org [mailto:pgsql-hackers-
> owner@postgresql.org] On Behalf Of Andrew Dunstan
> Sent: Friday, April 22, 2005 10:46 AM
> To: Dave Held
> Cc: pgsql-hackers@postgresql.org
> Subject: Re: [HACKERS] Woo hoo ... a whole new set of compiler
headaches!!
>
>
>
> Dave Held wrote:
>
> >>-----Original Message-----
> >>From: Alvaro Herrera [mailto:alvherre@dcc.uchile.cl]
> >>Sent: Friday, April 22, 2005 12:06 PM
> >>To: Tom Lane
> >>Cc: Dave Held; pgsql-hackers@postgresql.org
> >>Subject: Re: [HACKERS] Woo hoo ... a whole new set of compiler
> >>headaches!! :)
> >>
> >>[...]
> >>Why don't we rewrite Postgres in D?
> >>
> >>http://www.digitalmars.com/d/
> >>
> >>:-D
> >>
> >>
> >
> >I see the smiley, but moving to C++ isn't just about switching
> >to the latest fad language.
> >
>
> No, it's about moving to the fad language about 2 generations back ...

Language wars are about as much fun as operating system wars.
C and C++ are both nice languages.

> >First of all, you would literally
> >have to rewrite it to use D.  There would probably need to be
> >very little work to make the Postgres codebase a conforming set
> >of C++ programs (mostly renaming variables/types named 'class',
> >'virtual', 'bool', etc.).  Second, you can find a decent C++
> >compiler on virtually every platform that has a C compiler.
> >Third, C++ offers real advantages in type safety, exception
> >handling, resource management, and even performance.
> >
> >
>
> Unless you did a major rewrite it's hard to see any great advantages.
> There are over 600,000 lines of code in Postgres by my rough count.
The
> potential rewrite effort is enormous. A thorough job would probably
> consume a release cycle just on its own.

You could use C++ as "a better C" with very little effort (but there are
C++ keywords sprinkled here and there, so it would be a good month of
work for somebody).

> Also, "virtually every platform" isn't good enough - we have a number
of
> oddballs in our supported list, and it would have to include at least
> those.

There is a C++ compiler for everything you can think of and most things
you can't think of.  That's not really a problem.

The real problem is that the development team is a team of C
programmers, not C++ programmers.  That is the reason that a change
makes no sense at all.

> >Even doing something as simple as writing a stored procedure
> >in C is somewhat awkward because of all the boilerplate casting
> >that must be done.  I'm fairly certain that most of the macros
> >in the stored procedure interface could go away if a C++ API
> >were created.
> >
> >
> >
>
> On the downside, some of us (including me) have much more experience
in
> and ease with writing C than C++. I could certainly do it - I write
> plenty of Java, so OO isn't a closed book to me, far from it - but
> ramping up in it would take me at least some effort. I bet I'm not
alone
> in that.

This is the crux of the matter.  You will certainly not be alone here.
I (personally) prefer C++ to C, but I am comfortable in either language.
However, if you have a team of 100 C programmers and a huge C project,
it is a terrible mistake to ask them to use C++.
> So this would not be cost-free - very far from it.

Here, we clearly agree.  As a project scales larger and larger the
benefits of C++ loom greater and greater.  When your project consists of
millions of lines of code, then C++ is a much better choice.  But I
don't think PostgreSQL is going to scale to titanic size any time soon.
If it were, I would suggest the conversion, no matter how painful.
> cheers
>
> andrew
>
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