yelouafi

// Getter a :: () -> a

// gmap :: ((a -> b), Getter a), Getter b
function gmap(fn, getter) {
  return () => fn(getter())
}

// gcombine2 :: ((a,b) -> c, Getter a, Getter ab) -> Getter c
function gcombine2(fn, getter1, getter2) {

bvaughn

// This is an example of how to fetch external data in response to updated props,
// If you are using an async mechanism that does not support cancellation (e.g. a Promise).

class ExampleComponent extends React.Component {
  _currentId = null;

  state = {
    externalData: null
  };

bvaughn

// This is an advanced example! It is not typically required for application code.
// If you are using a library like Redux or MobX, use the container component provided by that library.
// If you are authoring such a library, use the technique shown below.

// This example shows how to safely update subscriptions in response to props changes.
// In this case, it is important to wait until `componentDidUpdate` before removing a subscription.
// In the event that a render is cancelled before being committed, this will prevent us from unsubscribing prematurely.

// We also need to be careful about how we handle events that are dispatched in between
// `getDerivedStateFromProps` and `componentDidUpdate` so that we don't put stale values into the `state`.