# Changelog
All notable changes to this project (as seen by library users) will be documented in this file.
The CHANGELOG is available on [Github](https://github.com/luc-tielen/souffle-haskell.git/CHANGELOG.md).
## [3.5.0] - 2022-06-04
### Changed
- souffle-haskell now supports Souffle version 2.3.
## [3.4.0] - 2022-05-15
### Changed
- Loosen the constraint that only types that are simple products that only
contain directly marshallable types like `Int32`, `Word32`, ... Now also
newtypes are allowed to be serialized, as well as product types inside other
product types (as long as all the fields implement the 'Marshal' typeclass).
### Fixed
- Check if a type is a simple product type consisting of only types supported by
Datalog. (This had a small bug for facts with more than 4 arguments.)
## [3.3.0] - 2022-02-27
### Added
- New `DerivingVia`-style API for binding to a Datalog program.
## [3.2.0] - 2022-02-20
### Added
- Add `Analysis` type for composing multiple Datalog programs.
### Changed
- souffle-haskell now supports Souffle version 2.2.
## [3.1.0] - 2021-09-30
### Changed
- souffle-haskell now supports Souffle version 2.1.
### Fixed
- Bug in some C++ assertions that caused the actual assertion message to be
wrongly computed.
## [3.0.0] - 2021-05-03
### Changed
- Optimized the underlying way of transferring facts between Haskell and C++.
- Add an extra `Submit a` constraint on `addFacts`, `addFact` and `containsFact`
when using compiled mode, similar to `Collect c` when using `getFacts`.
### Fixed
- Potential memory leak if an async exception occurred between the point of
allocating a pointer and wrapping it in a `ForeignPtr`.
### Removed
- Souffle EDSL (this is now available in the
[souffle-dsl](https://github.com/luc-tielen/souffle-dsl)
package). This is mostly done to improve compile times of this package.
## [2.1.0] - 2021-01-03
### Added
- Support Semigroup and Monoid instances for composing Souffle actions in
other ways.
- Add role annotations to handle types to avoid using `coerce` to change
the type of a Souffle handle.
### Changed
- souffle-haskell now supports Souffle version 2.0.2.
### Fixed
- Fix GHC 8.10 specific warnings and compile error.
## [2.0.1] - 2020-09-05
## Fixed
- Compiler flags in package.yaml that lead to a compile error.
## [2.0.0] - 2020-08-23
### Added
- The `Fact` typeclass now also requires you to specify the `FactDirection`.
This prevents inconsistent and buggy behavior when trying to use a fact in
an invalid way (e.g. trying to add an output-only fact).
- DSL for creating Soufflé programs directly from Haskell.
See the docs of `Language.Souffle.Experimental` for more information.
### Changed
- souffle-haskell now supports Soufflé version 2.0.1.
- `getFacts`, `findFact`, `addFact` and `addFacts` now have stricter
constraints in their type signatures to prevent invalid usage of facts.
- `runSouffle` for both compiled and interpreted mode and `runSouffleWith`
for interpreted mode have updated type signatures to be able to
automatically cleanup temporary files created while interacting with Souffle.
### Removed
- `init` function for both compiled and interpreted mode. Initialization is
now handled by the `runSouffle*` functions. This change makes automatic
cleanup of created files possible and prevents double initialization of
Souffle programs.
- `cleanup` function for interpreted mode, this is handled automatically now.
## [1.1.0] - 2020-07-26
### Added
- getFacts can now return facts in a fixed size array (from the array package).
- Added support for facts containing "unsigned" values.
- Added support for facts containing "float" values.
### Fixed
- The `run` function in `Language.Souffle.Interpeted` now always closes
stdout and stderr handles of the external souffle process.
### Removed
- `Language.Souffle` module is removed since it only existed due to legacy
reasons. This removal forces users to be explicit about the mode they are
using souffle-haskell in (interpreted or compiled mode). If you experience
compilation errors, rename all imports of `Language.Souffle` to
`Language.Souffle.Compiled`.
## [1.0.0] - 2020-07-09
### Changed
- Libraries using souffle-haskell are now "self-contained": if a project
depends on such a library, it will not require to also have Souffle installed.
- souffle-haskell now supports Soufflé version 2.0.0.
- `writeFiles` now takes an extra `FilePath` argument for writing facts to a
certain directory.
### Deleted
- Language.Souffle.TH module is deleted because it is no longer needed anymore
due to a change in the generated Souffle code. The generated code can now be
correctly integrated by adding the files to `cxx-sources`
in package.yaml / cabal file.
## [0.2.3] - 2020-05-21
### Changed
- Optimize performance when marshalling and unmarshalling facts.
## [0.2.2] - 2020-04-30
### Changed
- Fix compile time issue when generically deriving `Marshal` typeclass
for data types with more than 3 fields.
## [0.2.1] - 2020-04-25
### Changed
- Trimmed dependencies to make the library more lightweight.
## [0.2.0] - 2020-04-22
### Added
- Added Language.Souffle.Interpreted module for running Souffle programs in interpreted mode.
NOTE: For this mode the CSV fact files must use TAB (`'\t'`) characters as separators.
- In interpreted mode, you can configure where the library looks for datalog files or where
the souffle executable is located. For more information, see the `runSouffle` and `runSouffleWith`
functions in the Language.Souffle.Interpreted module.
### Changed
- Introduced Language.Souffle.Class module as separation of the typeclass and the
Language.Souffle.Compiled module to offer a uniform API in both interpreted and compiled mode.
## [0.1.0] - 2019-12-21
### Added
- Added Marshal instance for lazy and strict Text
### Changed
- getFacts can now return a vector instead of a list, based on type inference.
This allows for a more efficient representation in memory as well
as being able to allocate all needed memory once before collecting facts.
## [0.0.1] - 2019-10-23
### Added
- Initial version of the library