function-gvs-comparison.js

// the object to proxy
var obj = new SomeObject();

// standard proxy with same-name getter/setter
var stdProxy = {
  getXsetY: function (value) {
    if (arguments.length) {
      if (typeof value === 'number') {
        obj.y = value;
        return true;
      } else {
        return false;
      }
    } else {
      return obj.x;
    }
  }
}

// the same proxy using a GVS array in a Proxy constructor
var myPxy = new Proxy(obj, {
  getXsetY: ['x', 'number', 'y']
});

refactored-proxy-creation.js

function createProxyForAny(obj,cfg) {
  var pxy = {},
    i,
    getterFnc = function (prop) {
      return function () {
        return obj[prop];
      }
    },
    setterFnc = function (prop) {
      return function (value) {
        if (value) {
          obj[prop] = value;
          return true;
        } else {
          return false;
        }
      }
    };
  for (i in cfg) {
    if (cfg.hasOwnProperty(i)) {
      pxy['get' + i] = getterFnc(i);
      pxy['set' + i] = setterFnc(i);
    }
  }
  return pxy;
}

traditional-proxy-creation.js

function createProxy(obj) {
  return {
    getProp: function () {
      return obj.prop; 
    },
    setProp: function (value) {
      if (value) {
        obj.prop = value;
        return true;
      } else {
        return false;
      }
    }
  };
}

These gists are embedded in http://learnings-bemson.blogspot.com/2010/09/learning-to-open-source-via-proxy.html to demonstrate the GVS pattern used by the Proxy constructor.