[JS] pathVar: Utility for reading/writing nested object properties

pathVar.js

/*
  Utility for reading/writing nested object properties
  - Read:   pathVar(obj, 'some.path')
  - Write:  pathVar(obj, 'some.path', newVal)

  To automatically create the path when writing (similar to `mkdir -p`):
    pathVar(obj, 'some.new.path', newVal, true)

  Automatic path creation will fail if any part of the path already exists and
  is not an object.

Note: This only verifies the first argument is an 'object'. Because JavaScript
incorrectly returns `'object'` for arrays and regular expressions, you may want
to replace `typeof object` with something that ensures the object is a hash.
*/
var pathVar = (function() {
  var iteratePath, read, write;
  iteratePath = function(object, path, createPath) {
    var j, len, property, tail;
    if (createPath == null) {
      createPath = false;
    }
    if (typeof object !== 'object' || typeof path !== 'string') {
      console.error('[pathVar] invalid arguments');
      return Array(2);
    }
    if (path.indexOf('.') === -1) {
      return [object, path];
    }
    path = path.split('.');
    tail = path.pop();
    for (j = 0, len = path.length; j < len; j++) {
      property = path[j];
      if (!object.hasOwnProperty(property)) {
        console.log(createPath);
        if (!createPath) {
          return Array(2);
        }
        object[property] = {};
      }
      object = object[property];
    }
    return [object, tail];
  };
  read = function(object, path) {
    var key, parentObj, ref;
    ref = iteratePath(object, path), parentObj = ref[0], key = ref[1];
    if (parentObj && key) {
      return parentObj[key];
    }
  };
  write = function(object, path, value, createPath) {
    var key, parentObj, ref;
    if (createPath == null) {
      createPath = false;
    }
    ref = iteratePath(object, path, createPath), parentObj = ref[0], key = ref[1];
    if (!(parentObj && key)) {
      return;
    }
    parentObj[key] = value;
    return value;
  };
  return function(object, path, value, createPath) {
    var ref;
    if (createPath == null) {
      createPath = false;
    }
    if (arguments.length === 2) {
      return read(object, path);
    }
    if ((ref = arguments.length) === 3 || ref === 4) {
      return write(object, path, value, createPath);
    }
    return console.error('[pathVar] incorrect number of arguments');
  };
}());