function getIn (object, path) {
  var stack = path.split('.')
  while (stack.length > 1) {
    object = object[stack.shift()]
  }
  return object[stack.shift()]
}

function updateIn (object, path, value) {
  var current = object
  var stack = path.split('.')
  while (stack.length > 1) {
    current = current[stack.shift()]
  }
  current[stack.shift()] = value
  return object
}

function setPartialState (component, path, value) {
  component.setState(
    updateIn(component.state, path, value))
}

export default function linkState (el, path) {
  return {
    value: getIn(el.state, path),
    requestChange: setPartialState.bind(null, el, path)
  }
}