Generating rhyming couplets

couplets.js

var _ = require('underscore');
var RiTa = require('rita');
var lexicon = new RiTa.RiLexicon();
var rita = RiTa.RiTa;
var animals = require('./animals.json').animals;
Array.prototype.pick = function() {
  return this[Math.floor(Math.random()*this.length)];
};

animals = _.map(animals, function(animal) {
  // only include animals with the stress we're looking for
  return {
    name: animal,
    stress: rita.getStresses(animal)
  }
});

function get101Phrase(words) {
  var results = _.chain(words)
    .map(function(el) {
      var stress = rita.getStresses(el);
      var pos = rita.getPosTags(el)[0];
      if (stress === '1') {
        el = ['very ','rather ','really '].pick() + el;
        stress = '1/0/1';
      }
      else if (stress === '0/1') {
        el = ['so ','not ','quite '].pick() + el;
        stress = '1/0/1';
      }
      return {
        word: el,
        stress: stress
      };
    })
    // just get the meter we want
    .filter(function(el) {
      return el.stress === '1/0/1';
    })
    // just return the word, not the stress
    .map(function(el) {
      return el.word;
    })
    .value();
  return results;
}

function getAnimalsByStress(stress) {
  // filter our list of animals
  var results = _.filter(animals, function(animal) {
    // only include animals with the stress we're looking for
    return animal.stress === stress;
  });
  // map it so we're just returning a list of names, and not a list of name/stress objects
  return _.map(results, function(result) {
    return result.name;
  });
}

function a(word) {
  var result = 'a';
  var first = rita.getPhonemes(word)[0];
  if (first === 'a'
    || first === 'e'
    || first === 'i'
    || first === 'o'
    || first === 'u') {
    result = 'an';
  }
  return result + ' ' + word;
}

/*
var animal_101 = getAnimalsByStress('1/0/1').pick();
var animal_1 = getAnimalsByStress('1').pick();
var couplet = 'The body of ' + a(animal_101) + ', the wisdom of ' + a(animal_1);

console.log(couplet);
*/
//console.log(rita.getPosTags('apple'));

function getAdjRhymes(word) {
  var rhymes = lexicon.rhymes(word);
  return _.filter(rhymes, function(rhyme) {
    // only return rhymes that are tagged 'jj' (adjectives)
    return rita.getPosTags(rhyme)[0] === 'jj';
  });
}

function makeCouplet() {
  var animal_101 = getAnimalsByStress('1/0/1').pick();
  var animal_1 = getAnimalsByStress('1').pick();
  var couplet = 'The body of ' + a(animal_101) + ', the wisdom of ' + a(animal_1);
  var adjRhymes = getAdjRhymes(animal_1);
  if (adjRhymes.length === 0) {
    return makeCouplet();
  }
  var rhymes = get101Phrase(adjRhymes);
  if (rhymes.length === 0) {
    return makeCouplet();
  }
  couplet += '\nToday you join with Gryffindor since you are ' + rhymes.pick();
  return couplet;
}

console.log(makeCouplet());

function getWordsByStress(words, stress) {
  return _.filter(words, function(word) {
    // only include animals with the stress we're looking for
    return rita.getStresses(word) === stress;
  });
}