[Xapian-discuss] What does the "om" prefix mean?

[Olly Betts]

On Thu, Jul 16, 2009 at 05:21:38PM +0800, ????????? wrote:
> I'm new to xapian, and I just begin to read the source code.**
> I found a lot of names with "om" prefix. What does this mean?** I've
> searched for it but could not get the answer.thanx.

It's a historical relic, and doesn't mean anything useful now.

But if you're interested in how it came about, as the history page says,
Xapian is partly derived from the Open Muscat engine:

http://xapian.org/history

Before being released under the GPL, Open Muscat was internally known as
"Object Muscat" (because it was written in C++ with an OO API, which was
quite a change from its precursor "Muscat 3.6" which was written in BCPL
with a text command interface).

Back then C++ compilers didn't all support namespaces, so prefixes were
commonly used instead.  We used "om" for types and "Om" for classes,
originally standing for "Object Muscat", and later retroactively changed
that to be "Open Muscat".

It's also not entirely a coincidence that the first two people involved
in the "Object Muscat" project were myself and Martin (Porter)...

Cheers,
    Olly