What can I do to share code among views in CouchDB?

Example 1 -- utility methods

Jesse Hallett has some good utility methods, including

function dot(attr) {
  return function(obj) {
      return obj[attr];
  }
}

Array.prototype.map = function(func) {
  var i, r = [],
  for (i = 0; i < this.length; i += 1) {
    r[i] = func(this[i]);
  }
  return r;
};

...

Where can I put this code so every view can access it?

Example 2 -- constants

Similarly for constants I use in my application. Where do I put

MyApp = {
  A_CONSTANT = "...";
  ANOTHER_CONSTANT = "...";
};

Example 3 -- filter of a filter:

What if I want a one view that filters by "is this a rich person?":

function(doc) {
  if (doc.type == 'person' && doc.net_worth > 1000000) {
    emit(doc.id, doc);
  }
}

and another that indexes by last name:

function(doc) {
  if (doc.last_name) {
    emit(doc.last_name, doc);
  }
}

How can I combine them into a "rich people by last name" view?

I sort of want the equivalent of the Ruby

my_array.select { |x| x.person? }.select { |x| x.net_worth > 1,000,000 }.map { |x| [x.last_name, x] }

How can I be DRYer?