checkAccesor.js (http://twitter.com/#!/FGRibreau/status/105274933663375360)

checkAccesor.js

//Imperative

var checkAccessor1 = function(accesor) {
  var steps  = accesor.split('.');
  var cursor = steps[0];
  var acumulator = cursor;
  for (var j=1, len = steps.length;j<len;j++) {
    cursor     += '.' + steps[j];
    acumulator += ' && ' + cursor;
  }
  return acumulator;
}

console.log(checkAccessor1('obj.uno.dos.tres.prop'));

//With foldl1

var checkAccessor2 = function(accesor) {
  var steps  = accesor.split('.');
  var cursor = steps[0];
  return steps.slice(1).reduce(function(acumulator,current,index){
     cursor += '.' + current;
     return acumulator + ' && ' + cursor;
  },cursor);
}
console.log(checkAccessor2('obj.uno.dos.tres.prop'));

//With foldl

var checkAccessor3 = function(accesor) {
  var steps  = accesor.split('.');
  var cursor = '';
  return steps.reduce(function(acumulator,current,index){
    if (index === 0) {
      cursor = current;
      acumulator = current;
    }
    else {
      cursor += '.' + current;
      acumulator += ' && ' + cursor;
    }
    return acumulator;
  },'');
}
console.log(checkAccessor3('obj.uno.dos.tres.prop'));