Node.js REPL eval

I am trying to implement an evaluation into a Node.JS REPL. I am getting the error TypeError: Property 'eval' of object #<REPLServer> is not a function. Here is my source code:

repl.start("> ", socket, socket, true, function(cmd, context, filename, callback){
etc...

repl.start() takes an object with those options, not individual arguments:

e.g. (note the curly brackets)

repl.start({
  prompt: "node via stdin> ",
  input: process.stdin,
  output: process.stdout
});

see the example at: http://nodejs.org/docs/v0.8.4/api/repl.html#repl_repl_start_options