MongoDB simple mapReduce (counts chars in a wordlist)

mapreduce2.js

map = function(){
  word = this.word.split("");
  chars = {};

  for(var i in word)
    if(! chars[word[i]])
      chars[word[i]] = 1;
    else
      chars[word[i]]++;

  for(var c in chars)
    emit(c, chars[c]);
}

reduce = function(key, values){
  sum = 0

  for(var i in values)
    sum += values[i]

  return sum;
}

finalize = function(key, value){
  return value;
}