# 0.3.1.0 (2017-06-11)
* Add AllZip, htrans, hcoerce, hfromI, htoI.
These functions are for converting between related
structures that do not have common signatures.
The most common application of these functions seems
to be the scenario where a datatype has components
that are all wrapped in a common type constructor
application, e.g. a datatype where every component
is a `Maybe`. Then we can use `hfromI` after `from`
to turn the generically derived `SOP` of `I`s into
an `SOP` of `Maybe`s (and back).
* Add `IsProductType`, `IsEnumType`, `IsWrappedType`
and `IsNewtype` constraint synonyms capturing
specific classes of datypes.
# 0.3.0.0 (2017-04-29)
* No longer compatible with GHC 7.6, due to the lack of
support for type-level literals.
* Support type-level metadata. This is provided by the
`Generics.SOP.Type.Metadata` module. The two modules
`Generics.SOP.Metadata` and `Generics.SOP.Type.Metadata`
export nearly the same names, so for backwards compatibility,
we keep exporting `Generics.SOP.Metadata` directly from
`Generics.SOP`, whereas `Generics.SOP.Type.Metadata` is
supposed to be imported explicitly (and qualified).
Term-level metadata is still available, but is now usually
computed automatically from the type-level metadata which
contains the same information, using the function
`demoteDatatypeInfo`. Term-level metadata is unchanged
from generics-sop-0.2, so in most cases, even if your
code makes use of metadata, you should not need to change
anything.
If you use TH deriving, then both type-level metadata and
term-level metadata is generated for you automatically,
for all supported GHC versions.
If you use GGP deriving, then type-level metadata is
available if you use GHC 8.0 or newer. If you use GHC 7.x,
then GHC.Generics supports only term-level metadata, so
we cannot translate that into type-level metadata. In
this combination, you cannot use code that relies on
type-level metadata, so you should either upgrade GHC or
switch to TH-based deriving.
# 0.2.5.0 (2017-04-21)
* GHC 8.2 compatibility.
* Make `:.:` an instance of `Applicative`, `Foldable` and
`Traversable`.
* Add functions `apInjs'_NP` and `apInjs'_POP`. These are
variants of `apInjs_NP` and `apInjs'_POP` that return their
result as an n-ary product, rather than collapsing it into
a list.
* Add `hexpand` (and `expand_NS` and `expand_SOP`). These
functions expand sums into products, given a default value
to fill the other slots.
* Add utility functions such as `mapII` or `mapIK` that lift
functions into different combinations of identity and
constant functors.
* Add `NFData` (and lifted variants) instances for basic functors,
products and sums.
# 0.2.4.0 (2017-02-02)
* Add `hindex` (and `index_NS` and `index_SOP`).
* Add `hapInjs` as a generalization of `apInjs_NP` and `apInjs_POP`.
* Make basic functors instances of lifted classes (such as `Eq1` etc).
# 0.2.3.0 (2016-12-04)
* Add various metadata getters
* Add `hdicts`.
* Add catamorphisms and anamorphisms for `NP` and `NS`.
* TH compatibility changes for GHC 8.1 (master).
# 0.2.2.0 (2016-07-10)
* Introduced `unZ` to destruct a unary sum.
* Add Haddock `@since` annotations for various functions.
# 0.2.1.0 (2016-02-08)
* Now includes a CHANGELOG.
* Should now work with ghc-8.0.1-rc1 and -rc2 (thanks to
Oleg Grenrus).
* Introduced `hd` and `tl` to project out of a product, and
`Projection` and `projections` as duals of `Injection` and
`injections`.
# 0.2.0.0 (2015-10-23)
* Now tested with ghc-7.10
* Introduced names `hmap`, `hcmap`, `hzipWith`, `hczipWith` for
`hliftA`, `hcliftA`, `hliftA2`, `hcliftA2`, respectively.
Similarly for the specialized versions of these functions.
* The constraint transformers `All` and `All2` are now defined
as type classes, not type families. As a consequence, the
partial applications `All c` and `All2 c` are now possible.
* Because of the redefinition of `All` and `All2`, some special
cases are no longer necessary. For example, `cpure_POP` can
now be implemented as a nested application of `pure_NP`.
* Because of the redefinition of `All` and `All2`, the functions
`hcliftA'` and variants (with prime!) are now deprecated.
One can easily use the normal versions instead.
For example, the definition of `hcliftA'` is now simply
hcliftA' p = hcliftA (allP p)
where
allP :: proxy c -> Proxy (All c)
allP _ = Proxy
* Because `All` and `All2` are now type classes, they now have
superclass constraints implying that the type-level lists they
are ranging over must have singletons.
class (SListI xs, ...) => All c xs
class (SListI xss, ...) => All2 c xss
Some type signatures can be simplified due to this.
* The `SingI` typeclass and `Sing` datatypes are now deprecated.
The replacements are called `SListI` and `SList`.
The `sing` method is now called `sList`. The difference
is that the new versions reveal only the spine of the list, and
contain no singleton representation for the elements anymore.
For one-dimensional type-level lists, replace
SingI xs => ...
by
SListI xs => ...
For two-dimensional type-level lists, replace
SingI xss => ...
by
All SListI xss => ...
Because All itself implies `SListI xss` (see above), this
constraint is equivalent to the old `Sing xss`.
The old names are provided for (limited) backward
compatibility. They map to the new constructs. This will
work in some, but not all scenarios.
The function `lengthSing` has also been renamed to
`lengthSList` for consistency, and the old name is
deprecated.
* All `Proxy c` arguments have been replaced by `proxy c`
flexible arguments, so that other type constructors can be
used as proxies.
* Class-level composition (`Compose`), pairing (`And`), and
a trivial constraint (`Top`) have been added. Type-level map
(`Map`) has been removed. Occurrences such as
All c (Map f xs)
should now be replaced with
All (c `Compose` f) xs
* There is a new module called `Generics.SOP.Dict` that contains
functions for manipulating dictionaries explicitly. These can
be used to prove theorems about non-trivial class constraints
such as the ones that get built using `All` and `All2`. Some
such theorems are provided.
* There is a new TH function `deriveGenericFunctions` that
derives the code of a datatype and conversion functions, but
does not create a class instance. (Contributed by Oleg Grenrus.)
* There is a new TH function `deriveMetadataValue` that
derives a `DatatypeInfo` value for a datatype, but does
not create an instance of `HasDatatypeInfo`. (Contributed by
Oleg Grenrus.)
* There is a very simple example file. (Contributed by Oleg
Grenrus.)
* The function `hcollapse` for `NS` now results in an `a` rather
than an `I a`, matching the specialized version `collapse_NS`.
(Suggested by Roman Cheplyaka.)
# 0.1.1.2 (2015-03-27)
* Updated version bounds for ghc-prim (for ghc-7.10).
# 0.1.1.1 (2015-03-20)
* Preparations for ghc-7.10.
* Documentation fix. (Contributed by Roman Cheplyaka.)
# 0.1.1 (2015-01-06)
* Documentation fixes.
* Add superclass constraint (TODO).
* Now derive tuple instance for tuples up to 30 components.
(Contributed by Michael Orlitzky.)