Immutable
Frost supports first-class immutable types. All immutable types descend from the class
frost.core.Immutable. By subclassing Immutable, you impose some restrictions on your class:
- All fields must be defines or constants rather than variables
- All fields must themselves be immutable types
These restrictions combine to ensure that it is not possible to modify data in any instance of an immutable object. Immutable objects receive several benefits from this:
- They may be used as constants
- They may be freely passed between threads
- Various additional optimizations become available
And, of course, there's always the obvious "it's easier to reason about things when they can't change out from under you" benefit.