Changelog for endo-0.3.0.0

ChangeLog / ReleaseNotes

Introducing type :-> to simplify type signatures of endomorphism folding functions that restrict type of a result. (new)
Type class AnEndo moved in to a separate module Data.Monoid.Endo.AnEndo. Definitions are reexported by Data.Monoid.Endo.Fold, therefore providing backward compatible API. (change)
Introducing instance AnEndo a => AnEndo (Identity a). (new)
Introducing FromEndo type class for conversion of endomorphism in to a value. It is a dual to AnEndo type class. This type class resides in its own module Data.Monoid.Endo.FromEndo. (new)
Introducing ApplyEndo newtype that provides easier endomorphism evaluation in cases when there is an "obvious" default value. This type has its own module Data.Monoid.Endo.Apply that also provides various helper functions and type class instances. (new)
Providing Eq1, Ord1, Read1 and Show1 instances if built with transformers package >=0.5 or base >=4.9 (i.e. GHC

=8.0.1) is available. (new)
Providing Generic1 instance for WrappedFoldable. (new)
Introducing instance AnEndo a => AnEndo (Option a), but only when compiled with base >=4.9, since that is the first version of base which contains Semigroup. (new)
Bumped upper bound of transformers package to include 0.5.* versions. (change)
Synchronized API documentation of Data.Monoid.Endo.Fold with README. (trivial change)
Uploaded to Hackage: http://hackage.haskell.org/package/endo-0.3.0.0

API documentation ehancements and clarifications.
Explicit implementation of aDualEndo for instance AnEndo a => AnEndo (Maybe a).
Uploaded to Hackage: http://hackage.haskell.org/package/endo-0.2.0.1

Default implementation for anEndo method of 'AnEndo' type class, which is now defined as: anEndo = getDual . aDualEndo. As a consequence it is now possible to define complete instances of AnEndo by providing either anEndo or aDualEndo. (new, change)
Introducing associated type Result to FoldEndoArgs type class. This allows result of the whole folding to be explicitly stated in a type signature. (new, change)
Introducing functions embedEndoWith and embedDualEndoWith. Both can be used to simplify application of endomorphisms that are result of folding. (new)
- embedEndoWith :: (AnEndo e, EndoOperatesOn e ~ a) => (Endo a -> b) -> e -> b
- embedDualEndoWith :: (AnEndo e, EndoOperatesOn e ~ a) => (Dual (Endo a) -> b) -> e -> b
Introducing instance AnEndo (Proxy a), which is useful in cases when one needs to force constraint EndoOperatesOn args ~ a where a is the a from Proxy a. This is done by encoding value of Proxy in to identity endomorphism that operates on specified type a. (new)
Introducing instance (Monoid c, FoldEndoArgs r) => FoldEndoArgs (Const c r), which is useful in cases when one needs to discard the computation and return a constant instead. (new)
Bumping upper bounds on base and between, therefore it now builds on GHC 7.10 with base 4.8. (new)
Uploaded to Hackage: http://hackage.haskell.org/package/endo-0.2.0.0