June NovaRUG Meeting

Tonight at NovaRUG we had two presenters: Tom Copeland and Xandy Johnson. Tom spoke about extending Ruby with C extensions and Xandy spoke about Rake. Tom walked through the ‘evolution’ of his Revolution Ruby library which provides Ruby bindings for the GNOME Evolution PIM (via the e-book library). His first example was the straight-forward way of extending Ruby with C (the code example looked very similar to those in Chapter 21 of the Pick Axe). There’s also an article at OnLamp about extending Ruby with C. His second example was more interesting, for me at least – he showed how to use Ruby DL2 to export C functions into a Ruby module using pure Ruby code! It’s as easy as this:

require 'dl/import'

module Foo
extend Importer

dlload 'libc'

extern "size_t strlen(const char *)"

s = "Hello, World!"
puts "#{s} is #{Foo.strlen(s)} characters long."

After that, Tom spoke briefly about SWIG for Ruby. Unfortunately, he had difficulty getting it to work and no one else present had been successful with it (or was willing to speak about it). Xandy was up next with an excellent overview of Jim Weirich’s Rake. He started off with a nice poem entitled ‘Ode to Rake’ which I will not republish as he was going to send it over to Jim and I don’t want to ruin that (there were suggestions that _why should turn it into a song). Xandy provided an overview of other popular build tools like Make and Ant (and we all had a good time complaining about Ant). Next he delved into the Rakefile sytax (after reminding us that Rake is all Ruby; so anything you can do in Ruby you can do in Rake) and discussed tasks, file tasks, directory tasks, rules, FileLists, sh (for calling out to the shell), ruby (for invoking another Ruby interpreter), package, rdoc and gem. Near the end of his presentation, he winged his way through namespaces, dependency import and multitask. Overall it was an excellent introduction to Rake which whetted our appetites for a deeper dive into Rake. Next month I’ll be presenting on Rails RJS Templates, on July 19th.