From: "Alexandru E. Ungur" <alexandru@...>
Date: 2007-01-11T22:16:14+09:00
Subject: Re: Sharing constants between C and Ruby code

>>> sender: "Nathaniel Trellice" date: "Thu, Jan 11, 2007 at 09:01:50PM +0900" <<<EOQ
> Hello,
> 
> I'm new to ruby, but fairly experienced in C. I am using Ruby on Rails
> to chat to a postgres database. I have some C functions that I can run
> in the database backend. I would like to use constants defined in C
> header files, e.g "#define MY_CONSTANT 100" within ruby code. I know I
> can similarly define a constant in ruby, i.e. "MY_CONSTANT=100", but
> given that I have quite a few of these, and synchronising the two files
> could become tricky, is there some (preferably simple) clever way/hack
> that I can define constants in a single file and use them both in C and
> in Ruby?
Hello,

I've had a similar problem to solve when I had a mixed PHP/Ruby project.
I ended up using a separate file from both PHP and Ruby, like:

0 = some_constant
1 = some_other_constant
etc.

which was trivial to parse and turn into constants into either of them.
It actually made the project cleaner to have the constants defined like 
that so I ended up putting all the constants there not just the common
ones between PHP and Ruby scripts.

Later, for parsing that same definitions file from C, I found a nice 
library: http://sbooth.org/ccl/index.html


All the best,
Alex