Network generators in javascript

network-generator.js

/* jshint node:true */

var generators = {};

function range(first, last) {
  var c = {
    first: first,
    last: last,
    now: first,
    step: function(c) {
      var result = c.now;
      c.now++;
      if (c.now >= c.last) {
        c.now = c.last;
      }
      return result;
    }
  };
  c.source = c.step.toString();
  var fn = function() {
    return c.step(c);
  };
  fn.generator = c;
  label(fn);
  return fn;
}

// Per Kyle
function label(object) {
  setImmediate(function() {
    for (var key in global) {
      if (global[key] === object) {
        generators[key] = object;
      }
    }
  });
}

// If I use "var" here, "label" won't work. Apparently
// it's different in the console per Kyle
gen = range(1, 10);

// Yield so label can work

setImmediate(function() {

  console.log('party A calls the generator 5 times');

  while (true) {
    var result = gen();
    console.log(result);
    if (result === 5) {
      break;
    }
  }

  // Send it "over the network"
  var generatorsB = JSON.parse(JSON.stringify(generators, function(key, value) {
    if ((typeof(value) === 'function') && (value.generator)) {
      return { generator: value.generator };
    }
    return value;
  }));

  console.log('party B calls the generator 5 times');

  // On a second actual browser I would merge these
  // back into "window".

  var gen2 = function() {
    var gen = generatorsB.gen.generator;
    if (!gen.step) {
      // Have to wrap the function in parens for eval to
      // like it for some reason
      gen.step = eval('(' + gen.source + ')');
    }
    return gen.step(gen);
  };

  while (true) {
    var result2 = gen2();
    console.log(result2);
    if (result2 === 10) {
      break;
    }
  }
});