fluorine-lib/es/util/state.js

Reactive state and side effect management for React using a single stream of actions

var _state = {
  doNext: function doNext(action) {
    var reducer = this.reducer;


    var nextState = reducer(this.state, action);
    if (nextState === this.state) {
      return this;
    }

    this.next = Object.assign(Object.create(_state), {
      state: nextState,
      action: action,
      reducer: reducer
    });

    return this.next;
  }
};

export function createState(reducer, init) {
  return Object.assign(Object.create(_state), {
    reducer: reducer,
    state: init
  });
}

export function filterActions(start, filter) {
  var reducer = start.reducer;

  var anchor = start;

  while (anchor.next) {
    if (filter(anchor.next.action)) {
      // Recompute state
      anchor.next.state = reducer(anchor.state, anchor.next.action);
    } else {
      // Erase filtered action from history
      anchor.next.state = anchor.state;
      anchor.next.action = {};
    }

    anchor = anchor.next;
  }
}