Changelog for invariant-0.6.4

0.6.4 [2024.12.05]

The Template Haskell machinery now uses TemplateHaskellQuotes when building with GHC 8.0+ instead of manually constructing each Template Haskell Name. A consequence of this is that invariant will now build with GHC 9.8, as TemplateHaskellQuotes abstracts over some internal Template Haskell changes introduced in 9.8.

Loosen the Monad constraint in the Invariant(2) instances for Kleisli to an Invariant constraint.
Loosen the Comonad constraint in the Invariant2 instance for Cokleisli to an Invariant constraint.
Add Invariant instances for PastroSum, CopastroSum, Environment, FreeMapping, Pastro, and FreeTraversing from the profunctors library.
Add Invariant(2) instances for Copastro and Coyoneda from the profunctors library.

Add InvariantProfunctor and InvariantArrow newtypes that admit implementations of invmap that only require Profunctor or Arrow constraints, respectively. Also add top-level invmapProfunctor and invmapArrow functions.

Fix a bug in which deriveInvariant2 would fail on certain data types with three or parameters if the first two parameters had phantom roles.
Fix a bug in which deriveInvariant(2) would fail on sufficiently complex uses of rank-n types in constructor fields.
Fix a bug in which deriveInvariant(2) would needlessly reject data types whose two last type parameters appear as oversaturated arguments to a type family.

Implement foldMap' in the Foldable instance for WrappedFunctor when building with base-4.13 or later.

Data.Functor.Invariant.TH now derives invmap(2) implementations for empty data types that are strict in the argument.
When using Data.Functor.Invariant.TH to derive Invariant(2) instances for data types where the last type variables are at phantom roles, generated invmap(2) implementations now use coerce for efficiency.
Add Options to Data.Functor.Invariant.TH, along with variants of existing functions that take Options as an argument. For now, the only configurable option is whether derived instances for empty data types should use the EmptyCase extension (this is disabled by default).

invariant.cabal used to incorrectly state the license was BSD3 when it was in fact BSD2. This is now fixed.

Allow TH derivation of Invariant(2) instances for datatypes containing unboxed tuple types
Ensure Invariant(2) instances are in-scope when importing Data.Functor.Invariant
Add Invariant and Invariant2 instances for Kleisli and Cokleisli
Add Category and Arrow-like instances for WrappedProfunctor

Rewrote Data.Functor.Invariant.TH's type inferencer. This avoids a nasty GHC 7.8-specific bug involving derived Invariant(2) instances for data families.
Add Invariant instances for Data.Complex.Complex, Data.Monoid.Product, and Data.Monoid.Sum

Require bifunctors-5.2 and profunctors-5.2. Add Invariant(2) instances for newly introduced datatypes from those packages.
Add ProfunctorFunctor, ProfunctorMonad, ProfunctorComonad, Mapping, and Traversing instances for WrappedProfunctor
Add StateVar as a dependency. Add Invariant instances for StateVar and SettableStateVar.
Add Invariant instances for URec (added to GHC.Generics in base-4.9.0.0)

Add genericInvmap function (and make it the default implementation of invmap for Invariant instances) on GHC 7.2 or later
Make Tagged instance poly-kinded

Support deriving Invariant and Invariant2 instances with Template Haskell
Added invmapFunctor, invmapContravariant, invmap2Bifunctor, and invmap2Profunctor to make defining Invmap and Invmap2 instances somewhat easier
Added WrappedFunctor, WrappedContravariant, WrappedBifunctor, and WrappedProfunctor data types to allow use of invmap and invmap2 for data types that aren't Invariant or Invariant2 instances.
Added Invariant instances for lazy ST, ArrowMonad, Handler, Identity, First, Last, Alt, Proxy, ArgDescr, ArgOrder, and OptDescr
Added Invariant and Invariant2 instances for data types in the array, bifunctors, containers, profunctors, semigroups, stm, tagged, transformers, and unordered-containers libraries