Dart’s built_value provides powerful, convenient immutable values for Dart. The values might be immutable, but the package hasn’t been standing still! In the six months since I last wrote about built_value there have been ten major improvements to the package.
It’s impossible to deny that immutability is a hot topic in programming, especially front-end programming. Libraries like Immutable.js and other concepts like unidirectional data flow have argued it’s easier to reason about data when it doesn’t change underneath you: