# 0.2.3.0
* 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 (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.)