Should have mutable and non mutable collection types

[Kamal Hussain]

ES6 minor releases should include having options between mutable and non mutable collection. It can be useful for developing progressive web apps and mobile apps.

[Dr. Ralf S. Engelschall]

Yes, immutable collections can be useful for ECMAScript. But you have to propose this to the ECMAScript standardization group. This es6-features project just shows the features of ECMAScript 6, nothing more, nothing less. We do not standardize ECMAScript. We are unrelated to the standardization group.