Aureliano Calvo wrote:
> Now I see that if I can transform all the <"a#{expression}c"> in <"a"
> + (expression) + "c"> in a ruby source code string, I could change
> expression with "a#{expression}c" in "a" + clever_stuff(expression) +
> "c" and use my changed + method in Strings. Is there an easy way to
> manipulate ruby code in ruby to do this?

Maybe you can take a look at ParseTree to decompose a dynamic string 
into its components:

  require "rubygems"
  require "parse_tree"
  class Foo
    def foo
      "interpolation: #{42}!"
    end
  end
  ParseTree.new.parse_tree(Foo)
=> [[:class, :Foo, [:const, :Object], [:defn, :foo, [:scope, [:block, 
[:args], [:dstr, "interpolation: ", [:lit, 42], [:str, "!"]]]]]]]

Daniel