seamless-immutable

Immutable JS data structures which are backwards-compatible with normal Arrays and Objects. Use them in for loops, pass them to functions expecting vanilla JavaScript data structures, etc. Whenever you deeply clone large nested objects, it should typically go much faster with Immutable data structures. This is because the library reuses the existing nested objects rather than instantiating new ones. In the development build, objects are frozen. The development build also overrides unsupported methods (methods that ordinarily mutate the underlying data structure) to throw helpful exceptions. We generally recommend to use the "development" build that enforces immutability (and this is the default in Node.js). Only switch to the production build when you encounter performance problems. By popular demand, functions, errors, dates, and React components are treated as immutable even though technically they can be mutated.