transform a list of names into an alphabet-keyed dictionary.

alphabet.js

// transform a list of names into an alphabet-keyed dictionary.
// e.g. input is 
// 
// var list = ["Elsie Chambers", "Gene Keller", "Glen Hall", "Lawrence Burke", "Lenora Robbins", "Lillian Stone", "Lucy Roberson", "Mario Curry",
// "Shawn Matthews", "Terry Joseph"]
//
// asAlphabetDictionary(list) =>
// {"A":["Adrian Stanley"],"F":["Fred Houston"],"H":["Hilda Hart"],
// "I":["Irene Coleman"],"J":["Jeffery Castillo","Jon Floyd","Jonathan 
// Conner"],"L":["Leon Higgins"],"N":["Nettie Jensen"],"S":["Sally
// Simon"]} 
//
// by miraculixx at github
var genNames = function(count) {
    var list = [];
    for(var i = 0; i < count; i++) {
        list.push(chance.name());
    }
    return list;
};

var asAlphabetDictionary = function(list, full) {
    var dict = {};
    if(full) {
        // get alphabet A..Z
        var alpha = String.fromCharCode.apply(this, _.range(65, 65+26));
        _.each(alpha.split(''), function(v) {
            dict[v] = new Array();
        });
    }
    list.sort();
    _.each(list, function(v, k, l) {
        var letter = v.substring(0,1).toUpperCase();
        if(!full && !(letter in dict)) {
            dict[letter] = new Array();
        }
        dict[letter].push(v);
    });
    return dict;
};

var list = genNames(5);
var dictSmall = asAlphabetDictionary(list, false);
var dictFull = asAlphabetDictionary(list, true);
console.log(list);
console.log(JSON.stringify(dictFull));
console.log(JSON.stringify(dictSmall));

I'm inclined to think there must a more straight forward way using _.map/_.reduce, anyone?