maybe_without_objects.js

function type(obj) {
  var obj_type = typeof obj;
  return({ is        : function(type) { return obj_type === type; },
           is_object : function()     { return obj_type === "object"; },
           is_func   : function()     { return obj_type === "function"; },
           is_string : function()     { return obj_type === "string"; }});
};
 
 
function maybe(item) {
  return({
    result: function(accessor, __default) {
      if (!item)
        return type(accessor).is_func() ? __default : accessor;
      else
        return type(accessor).is_func() ? accessor(item) : item;
    },
    
    select: function(accessor) {
      if (!item) 
        return maybe(null);
      else if (type(accessor).is_string()) 
        return maybe(item[accessor]);
      else 
        return maybe(accessor(item));
    }
  });
};