On Oct 27, 2003, at 11:43 AM, George Gambill wrote:

> Chris (Gehlker), Thanks for your insight with Ruby.  The fact that we 
> can
> create a Ruby system, which is normally interruptive, and convert 
> (maybe not
> the right word) to "C" thereby allowing us to end up with a compiled 
> system,
> makes Ruby very attractive to me.
>
> The opportunities (we don't have problems, only opportunities) with the
> equipment taught us a very valuable lesson.  Would it help if (in the
> future) all presentations (and demonstrations) were burned to CD's 
> thereby
> providing flexibility the day of the event.  Chris, Thanks again.

This is a great idea:

For those still looking for an example of a closure, here is one:

#   Closure.rb

#   A contrived example of a closure in ruby.
#   Since the following definition is not inside
#   a class definition, it is defining a new method
#   of the base class, Object.

def nTimes(aThing)
     return proc { |n| aThing * n }
end

#   What just happened there is that the 'proc'
#   method converted the the simple block
#   ' { |n| aThing * n } into a Proc object.
#   Proc objects are closures: they close over
#   all the context that applied when the block
#   was *defined* including the value of self,
#   and any methods, variables and constants
#   that apply.

#   Let's try it here where aThing is out of
#   scope because it was local to the nTimes
#   method.

p1 = nTimes(23);
puts p1.call(3);    #puts is short for 'put string'
puts p1.call(4);    #we only need it if we aren't
                     #running interactive
p2 = nTimes("Hello ");
puts p2.call(3);

#   run like 'ruby Closure.rb
#   output looks like
#
#   69
#   92
#   Hello Hello Hello