Coffeescript helpers`

helpers.coffee

sum = (arr) -> arr.reduce ((a,b) -> a+b), 0
cmp = (x, y) -> (if x > y then 1 else (if x < y then -1 else 0))
keys = Object.keys(list).sort((a,b)-> list[b]-list[a]) # sort by object value DESC

# initial array with default value
_.range(3).map(function () { return 'a' })

# string to bigram array
toBigrams = (str) ->
  oneGrams = str.split('')
  bigrams = []
  for i in [1...oneGrams.length]
    bigrams.push [oneGrams[i-1], oneGrams[i]]
  (if bigrams.length then bigrams else oneGrams)
  
# zero pad
String('00'+3).slice -2 # output: 03

String.prototype.replaceHtmlEntites = () ->
  s = @
  translateRe = /&(nbsp|amp|quot|lt|gt);/g
  translate   =
    'nbsp': ' '
    'amp' : '&'
    'quot': '"'
    'lt'  : '<'
    'gt'  : '>'
  return s.replace translateRe, (match, entity) ->
    return translate[entity]