Using the standard shapes example, I posted some code in C showing how to do runtime polymorphism using pointers to functions. I also include C++ and Java examples. Then everybody got in the act and we ended up with this (onestepback.org/articles/poly).

Some of the source files are missing, and I’ll replace them when I can. In the meantime, enjoy.

Feel free to provide feedback at jweirich@one.net.

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I can answer that question because I just did it for the UML system you see here.

Here’s what I loaded …

• I have download most of my brain into Emacs macros, so working without emacs for any length of time is not acceptable. Fortunately, a quick ‘apt-get install emacs21’ and a working emacs system becomes available.
• After loading emacs, I grabbed the .emacs file (and all of its supporting libraries) from my desktop system.
• My overall plan for this UML system is to use it as my web host. That means that apache is required. Grabbing apache with apt-get was simple.
• I plan to base my web site around a Ruby based blogging package called Rublog. That means Ruby will be needed. Since I tend to track the latest version of Ruby a little more closely than Debian does, I normally install Ruby by hand from source. Fortunately, installing Ruby is trivial. I just downloaded the source (from www.ruby-lang.org), and did the standard configure/make/make install commands.
• Next I needed the Rublog software. I had been playing with Rublog on my laptop, so I had the configuration pretty well decided by that point. I just copied the laptop setup to the UML system.
• Finally, Rublog needs RDoc to render any RDoc postings. A quick visit to the Ruby Application Archive to grab RDoc and I was good to go.

And that completed my first phase of setups. I had to do a little reading on setting up iptables and a bit of configuration with apache. The result is what you see here.

So, what packages do you need to work with.

… from the Edge