From: "rpardee@..." <rpardee@...>
Date: 2008-01-18T10:46:04+09:00
Subject: passing method references in python & ruby

Hey all,

Kind of an idle, syntax comparison question here...

In python, you can apparently pass method references around very
easily.  So imagine you have these 2 functions defined:

   def firstWay(arg1, arg2)
      return 'Tastes great.'

   def secondWay(arg1, arg2)
      return 'Less filling.'

Then you can define a method that takes a method name as an argument,
and calls it just by throwing parens (and any expected arguments of
course) after it.

   def doStuff(whichway, first_arg, second_arg)
      return whichway(first_arg, second_arg)

So calling:

   puts doStuff(firstWay, None, None)

Would result in 'Tastes great.'

What's the most graceful way to do this sort of thing in ruby?  I
tried passing in e.g., firstWay.to_proc, but that got me a complaint
about not having enough arguments on the call.  I can imagine doing,
e.g.,

   first_pointer = Proc.new do |foo, bar|
      return firstWay(foo, bar)
   end

One for each alternate method & passing one of those in.  I can also
imagine having doStuff take a block that would call the desired
function & yielding out to that.  But neither of those are as pretty
as the python I think.  Are those my best options in ruby, or is there
another way?

Thanks!

-Roy