Reselect

Simple “selector” library for Redux (and others) inspired by getters in NuclearJS, subscriptions in re-frame and this proposal from speedskater. Selectors can compute derived data, allowing Redux to store the minimal possible state. Selectors are efficient. A selector is not recomputed unless one of its arguments changes. Selectors are composable. They can be used as input to other selectors. Reselect provides a function createSelector for creating memoized selectors. createSelector takes an array of input-selectors and a transform function as its arguments. If the Redux state tree is mutated in a way that causes the value of an input-selector to change, the selector will call its transform function with the values of the input-selectors as arguments and return the result. If the values of the input-selectors are the same as the previous call to the selector, it will return the previously computed value instead of calling the transform function.