The Functor class is used for types that can be mapped over. Instances of Functor should satisfy the following laws:
> fmap id == id
> fmap (f . g) == fmap f . fmap g
The instances of Functor for lists, Data.Maybe.Maybe and System.IO.IO satisfy these laws.
Functors: uniform action over a parameterized type, generalizing the map function on lists.
This package has been subsumed by semigroupoids
Simple functor combinators, their derivatives, and their use for tries Maybe split out derivatives and/or tries later.
This is the Data.FunctorM module from 6.6's base, deleted from HEAD still used by some projects (notably jhc); this package can be used for compatibility.
Alternative syntax for Functor and Applicative. Includes Caleskell idioms like (.) = fmap, and also extensions like (.:) = fmap . fmap and (&) = (*).
This library provides a Cofunctor class useful for types that are sinks or make use of IO effects. See documentation for details. Some supporting constructions are also provided.
This package allows you to run a form created by digestive functors against a JSON document that has been parsed by Aeson.
For changes, please see http:github.comocharleschangelog.md
Blaze frontend for the digestive-functors library
Happstack backend for the digestive-functors library
Heist frontend for the digestive-functors library
This is an HSP frontend for the digestive-functors library.
Scotty backend for the digestive-functors library
Snap backend for the digestive-functors library
A free functor is a left adjoint to a forgetful functor. It used to be the case that the only category that was easy to work with in Haskell was Hask itself, so there were no interesting forgetful functors.
But the new ConstraintKinds feature of GHC provides an easy way of creating subcategories of Hask. That brings interesting opportunities for free (and cofree) functors.
The examples directory contains an implementation of non-empty lists as free semigroups, and automata as free actions. The standard example of free higher order functors is free monads, and this definition can be found in Data.Functor.HFree.
Generate (derive) fmap, foldMap and traverse for Bifunctors, Trifunctors, or a functor with any arity
This package has been absorbed into profunctors 4.0
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