Incrementing object properties

utils.js

// Ensure object obj[prop] = {}
function _obj(obj, prop) {
  if (obj[prop] == null) obj[prop] = {}
  return obj[prop]
}
// Ensure number obj[prop] (+= val or = val)
function _diff(obj, prop, val) {
  if (obj[prop] == null) obj[prop] = val
  else obj[prop] += val
}
function diff(obj, prop, d) {
  _diff(obj, prop, d)
}
function inc(obj, prop) {
  _diff(obj, prop, 1)
}
function incOf(obj, prop, prop2) {
  inc(_obj(obj, prop), prop2)
}
function incMerge(obj, obj2) {
  var arr = Object.keys(obj2)
  arr.forEach(function (prop) {
    inc(_obj(obj, prop), obj2[prop])
  })
}
function incMergeOf(obj, obj2, prop) {
  incMerge(_obj(obj, prop), obj2)
}
function incEach(obj, arr) {
  arr.forEach(function (prop2) {
    inc(obj, prop2)
  })
}
function incEachOf(obj, prop, arr) {
  incEach(_obj(obj, prop), arr)
}
function incOfEach(obj, arr, prop2) {
  arr.forEach(function(prop) {
    incOf(obj, prop, prop2)
  })
}
function incEachOfEach(obj, arr) {
  var temp
  function incIfDifferent(prop) {
    if (prop !== temp)
      incOf(obj, prop, temp)
  }
  arr.forEach(function (prop2) {
    temp = prop2
    arr.forEach(incIfDifferent)
  })
}

exports.diff = diff
exports.inc = inc
exports.incOf = incOf
exports.incMerge = incMerge
exports.incMergeOf = incMergeOf
exports.incEach = incEach
exports.incEachOf = incEachOf
exports.incOfEach = incOfEach
exports.incEachOfEach = incEachOfEach