# bbotk 1.9.0

* feat: Allow `"learn"` tag (direction=0) alongside minimize/maximize in `Codomain`.
* feat: Add new base class `EvalInstance` from which `OptimInstance` now inherits. `EvalInstance` keeps information about a process that evaluates an `Objective` while not necessarily optimizing it.
* feat: Exporting formerly internal `choose_search_space()` function.
* feat: Use `mlr3misc` error classes for errors and warnings.
* compatibility: Compatible with `rush` 1.0.0.
* fix: Terminator print method works correctly now.

# bbotk 1.8.1

* fix: Any Conditions work with `OptimizerLocalSearch` now.


# bbotk 1.8.0

* feat: Add `on_optimizer_queue_before_eval` and `on_optimizer_queue_after_eval` stages to `CallbackAsync` and `CallbackBatch`.
* fix: Start phase of `rush` worker.

# bbotk 1.7.1

fix: Imbalanced protection and casting in C code.
fix: Load required packages in worker loop.

# bbotk 1.7.0

* BREAKING CHANGE: Replace `OptimizerBatchLocalSearch` with a faster C implementation.
* feat: Add `par` parameter to `OptimizerGenSA`.
* BREAKING CHANGE: Replace `start` parameter from  `OptimizerNloptr` with `x0` parameter.
* feat: Expose internal termination criteria of `Optimizer`s.
* feat: Store required packages in `Objective$packages`.
* feat: Fail queued and running points when optimization is terminated.
* fix: Pass `n_workers` to `rush`.
* feat: Kill `rush` worker after optimization.
* feat: Add tiny logging mode.

# bbotk 1.6.0

* BREAKING CHANGE: The mlr3 ecosystem has a base logger now which is named `mlr3`.
  The `mlr3/bbotk` logger is a child of the `mlr3` logger and is used for logging messages from the `bbotk` and `mlr3tuning` package.
* feat: Classes are now printed with the `cli` package.
* fix: Prevent switching of `xss` and `constants`.
* fix: Add saveguard on `OptimizerNloptr` bounds.
* feat: Allow numerical gradient approximation in `OptimizerNloptr`.

# bbotk 1.5.0

* compatibility: irace 4.1.0
* compatibility: rush 0.2.0
* refactor: Replace `Codomain$maximization_to_minimization` with `$direction` field.
* feat: Save `ArchiveAsync` to a `data.table` with `ArchiveAsyncFrozen`.

# bbotk 1.4.1

* compatibility: irace 4.0.0

# bbotk 1.4.0

* feat: Add `OptimizerBatchChain` that runs multiple optimizers sequentially.
* refactor: Only pass `extra` to `$assign_result()`.

# bbotk 1.3.0

* feat: Add new stage `on_result_begin` to `CallbackAsyncTuning` and `CallbackBatchTuning`.
* refactor: Rename stage `on_result` to `on_result_end` in `CallbackAsyncTuning` and `CallbackBatchTuning`.
* docs: Extend the `CallbackAsyncTuning` and `CallbackBatchTuning` documentation.

# bbotk 1.2.0

* feat: `ContextBatch` and `ContextAsync` have a `result_extra` field now to access additional results passed to the instance.
* refactor: Additional information are passed with `extra` to `OptimInstance$assign_result()`.

# bbotk 1.1.1

* feat: The optimizers passes additional information to `OptimInstance$assign_result()` method.

# bbotk 1.1.0

* docs: Move vignette to mlr3book.
* feat: Add hypervolume stagnation terminator `trm("stagnation_hypervolume")`.
* feat Add local search optimizer `opt("local_search")`.
* refactor: Remove unused fields from callbacks.
* fix: Add `"on_optimization_end_batch"` stage to `CallbackBatch`.

# bbotk 1.0.1

* refactor: extra columns in results.

# bbotk 1.0.0

* feat: Introduce asynchronous optimization with the `OptimizerAsync` and `OptimInstanceAsync` classes.
* BREAKING CHANGE: The `Optimizer` class is `OptimizerBatch` now.
* BREAKING CHANGE: The `OptimInstance` class and subclasses are `OptimInstanceBatch*` now.
* BREAKING CHANGE: The `CallbackOptimization` class is `CallbackBatch` now.
* BREAKING CHANGE: The `ContextOptimization` class is `ContextBatch` now.
* BREAKING CHANGE: Remove `ArchiveBest` class and `keep_evals` parameter from `OptimInstance`.

# bbotk 0.8.0

* fix: `OptimizerIrace` failed with logical parameters and dependencies.
* refactor: Optimize the runtime of `archive$best()` method and add ties method.
* compatibility: Work with new paradox version 1.0.0

# bbotk 0.7.3

* fix: `OptimInstance$print()` errored when the search space was empty.

# bbotk 0.7.2

* fix: Standalone `Tuner` and `FSelector` were rejected by `ContextBatch`.

# bbotk 0.7.1

* feat: Data unrelated to a specific point evaluation can be written to `Archive$data_extra`.

# bbotk 0.7.0

* fix: `Terminator$format(with_params = TRUE)` printed an empty list when no parameter was set.
* refactor: `OptimizerIrace` automatically added the `instances` parameter to `Objective$constants`.
  From now on, the `instances` parameter can be also set manually.
* BREAKING CHANGE: `branin(xs)` is now `branin(x1, x2, noise)` and `branin_wu(x1, x2, fidelity)`.
* feat: Add `ObjectiveRFunMany` that can evaluate a list of configurations with a user supplied function.
* fix: If all configurations were missing a parameter, `ObjectiveRFunDt$eval_many()` did not create a column with `NA` for the missing parameter.
* refactor: The default of `digits` in `OptimizerIrace` is 15 now to avoid rounding errors.
* refactor: The bounds of double parameters were processed with only 4 decimal places in `OptimizerIrace`.
  By default, the bounds of double parameters are represented with 15 decimal places now.
  The `digits` parameter of `OptimizerIrace` also changes number of decimal places of the bounds now.

# bbotk 0.6.0

* fix: `OptimizerIrace` did not work with parameters with multiple dependencies.
* feat: Add new callback that backups the archive to disk to `mlr_callbacks`.
* feat: Create custom callbacks with the `callback_batch()` function.

# bbotk 0.5.4

* feat: Add `OptimizerFocusSearch` that performs a focusing random search.

# bbotk 0.5.3

* feat: `Optimizer` and `Terminator` objects have the field `$id` now.

# bbotk 0.5.2

* refactor: The `$print()` method of `OptimInstance` omits unnecessary columns now.
* fix: The `$clear()` method of `OptimInstance` raised an error.
* fix: The `$clear()` method of `Archive` missed to reset the `$start_time` field.
* feat: `Optimizer` and `Terminator` objects have the optional field `$label` now.
* feat: `as.data.table()` functions for objects of class `Dictionary` have been extended with additional columns.
* feat: Add a `as.data.table.DictionaryTerminator()` function.

# bbotk 0.5.1

* fix: The return of the `$.status()` method of `TerminatorRunTime` and `TerminatorClockTime` was not in a consistent unit.
  The return is in seconds from now on.
* fix: The number of evaluations was recorded as 0 in the log messages when the search space was empty.
* feat: Add a `as.data.table.DictionaryOptimizer()` function.
* feat: New `$help()` method which opens the manual page of an `Optimizer`.

# bbotk 0.5.0

* feat: Add `$nds_selection()` method to `Archive`.
* feat: New `Codomain` class that allows extra parameters.
* refactor: Objective values were automatically named.
  From now on, only unnamed returns of `ObjectiveRFun` are named.
* fix: `OptimInstance`, `Archive` and `Objective` objects  were not cloned properly.
* refactor: The fields `$param_classes`, `$properties` and `$packages` of `Optimizer` objects are read-only now.
* feat: The `branin()` function is exported now.

# bbotk 0.4.0

* feat: The search space and domain can now be empty.
* feat: The budget of `TerminatorEvals` can now be changed depending on the dimension of the search space with the parameter `k`.
* feat: Add `bb_optimize()` function.
* feat: Add `OptimizerIrace` which calls `irace::irace` from the `irace` package.

# bbotk 0.3.2

* refactor: Internal changes.

# bbotk 0.3.1

* feat: Add `$clear()` method to `OptimInstance` to reset the instance.
* refactor: Prettier `$print()` methods.
* feat: Assertions on overlapping and reserved names in domain and codomain.

# bbotk 0.3.0

* feat: The check of points and results can now be disables with the `check_values` flag in `OptimInstance`, `OptimInstanceSingleCrit`, `OptimInstanceMultiCrit`, `ObjectiveRFun` and `ObjectiveRFunDt`.
* refactor: The `data.table` within the `Archive` can now be accessed with `$data`.
* refactor: The `m` parameter of `Archive$best()` is renamed to `batch`.
* feat: New `ArchiveBest` class which only stores best scoring evaluation instead of all evaluations
* refactor: The runtime is reduced when `ObjectiveRFunDt` is used with a domain without trafo.
* fix: Add support for `ParamUty` in `OptimizerDesignPoints`.
* feat: The start points for `OptimizerCmaes` and `OptimizerNloptr` can now be randomly created or from center of the search space.
* feat: The `$optimize()` method supports progress bars via the package `progressr`.

# bbotk 0.2.2

* refactor: Remove dependency on orphaned package `bibtex`.
* feat: Add `OptimizerCmaes` which calls `adagio::pureCMAES` from the `adagio` package.

# bbotk 0.2.1

* refactor: Compact in-memory representation of R6 objects to save space when saving mlr3 objects via saveRDS(), serialize() etc.
* refactor: Warning and error messages when upstream package of `Optimizer` is not installed.

# bbotk 0.2

* First version of the Black-Box Optimization Toolkit
