From: Joseph McDonald <joe@...>
Date: 2002-09-11T04:57:22+09:00
Subject: Re: Refactoring Ruby


RK> class Foo
RK>     def [](index)
RK>         puts "Warning...[] called from #{caller}"
RK>         get_with_index(index)
RK>     end
RK>     def get_with_index(index)
RK>         #do something different
RK>     end
RK> end

Cool idea.  You could probably take it a step further and have it
rewrite the code at that point.  To do it right you would probably
have to have a parser that can parse ruby code.  Here's a dangerous
hack that can easily break code:

class Foo
    def [](index)
      puts "Warning...[] called from #{caller}"

      # now fix the offending line in the file.
      caller_file, caller_line = caller[0].split(":")
      caller_line = caller_line.to_i - 1  # each_with_index zero based
      File.open("#{caller_file}.new", "w") do |newfile|
        File.open(caller_file,"r").each_with_index do |line, lineno|
          if caller_line == lineno
            newfile.print "# XXX CHANGED FROM: #{line}"
            line.gsub!(/\[#{index}\]/,".get_with_index(#{index})")
          end
          newfile.print line
        end
      end
      # could be dangerous...
      File.rename(caller_file, "#{caller_file}}.old")
      File.rename("#{caller_file}.new", caller_file)

      get_with_index(index)
    end

    def get_with_index(index)
        #do something different
    end
end

f = Foo.new

blah = f[10]

regards,
-joe