3.4.2 - 2025-07-14 * Added support for `Quickcheck-2.16`.

4.0.0 - 2025-03-12 * **BREAKING**: Removed `Realized` - To migrate uses of `Realized` with `IOSim`, index the state type on the choice of `RunModel` monad and index the relevant types: ``` -- Turn: data ModelState = State { threadId :: Var ThreadId } -- Into: data ModelState m = State { threadId :: Var (ThreadId m) } ``` * **BREAKING**: Moved `Error state` from `StateModel` to `RunModel` and indexed it on both the `state` and the monad `m` * **BREAKING**: Changed `PerformResult` from `PerformResult (Error state) a` to `PerformResult state m a` * Added a `moreActions` property modifier to allow controlling the length of action sequences.

* Expose `IsPerformResult` typeclass [#70](#70) 

* Added some lightweight negative-shrinking based on a simple depende… …ncy analysis. * Added the option to return errors from actions by defining `type Error state`. When this is defined `perform` has return type `m (Either (Error state) (Realized m a))`, when it is left as the default the type remains `m (Realized m a)`. * Changed `withGenQ` to _require_ a predicate when defining a `Quantification`. **Note**: This is technically a breaking change as the interface changed

Bump versions and add changelog entry 

Bump version to 3.3.0 

* Added support for negative testing via `validFailingAction` and `po… …stconditionOnFailure` callbacks in `StateModel` and `RunModel`.

* Added instances for `HasVariables` with custom error messages to av… …oid the issue of missing `Generic` instances causing difficult to understand type errors.

* **BREAKING**: Change the type of `postcondition` to allow you to express property monitoring (e.g. stats or counterexamples) in the postcondition itself - rather than duplicating code for counterexamples in the `monitoring` function.

Release notes