Functional Immutable

Iteratee-first data-last null-safe curried functions wrapper for immutable.js

Are you using Immutable.js with React and Redux? Take a look at react-redux-immutabe for mapping your immutable state to your props without performance hit.

Installation

Functional Immutable relies on a single peer dependency, it requires Immutable 3 already installed.

npm install --save functional-immutable

Usage

Functional Immutable aims to provide all immutable object methods as curried, data-last, null-safe functions. It is designed to work seamlessly in an point-free style program.

For example :

import fp from "lodash/fp";
import Immutable from "immutable";
import * as fi from "functional-immutable";
 
const immutableObject = Immutable.fromJS({
  user: {
    lastName: "Skywalker"
  }
});
 
export const getUppercaseLastName = fp.flow(
  fi.getIn(['user', 'lastName']),
  fp.defaultTo('Doe'),
  fp.toUpper,
);
 
getUppercaseLastName(immutableObject); // SKYWALKER
getUppercaseLastName(); // DOE

Also, Functional Immutable is non-opinionated and will work with any point-free library such as Ramda.

import R from "ramda";
import Immutable from "immutable";
import * as fi from "functional-immutable";
 
const immutableObject = Immutable.fromJS({
  user: {
    lastName: "Skywalker"
  }
});
 
export const getUppercaseLastName = R.compose(
  R.toUpper,
  R.defaultTo('Doe'),
  fi.getIn(['user', 'lastName']),
);
 
getUppercaseLastName(immutableObject); // SKYWALKER
getUppercaseLastName(); // DOE

It should also shine with Redux selectors such as reselect or re-reselect.

import { createSelector } from "reselect";
import Immutable from "immutable";
import * as fi from "functional-immutable";
 
const applicationState = Immutable.fromJS({
  user: {
    lastName: "Skywalker"
  }
});
 
export const getUppercaseLastName = createSelector(
  fp.flow(
    fi.getIn(['user', 'lastName']),
    fp.defaultTo('Doe')
  ),
  fp.toUpper
);
 
getUppercaseLastName(applicationState); // SKYWALKER
getUppercaseLastName(); // DOE

Api Changes

delete => deleteAt

delete being a reserved keyword, the delete method has been re-exported as deleteAt.

Contribute

Something missing?

Found a missing function? Feel free to contribute by opening a Pull Request.

This wrapper relies on naïve re-exports of Immutable object methods. Here is how to add a missing method called missing.

In index.js add the following:

export const missing = (...vargs) => data => safeApply(data, 'missing', vargs);

Test coverage

You can also contribute by writing unit tests, for example by rewriting existing Immutable 3 Unit Tests using functional-immutable.