functor-apply: Applicative sans pure, Monad sans return, Alternative sans empty
Provides a wide array of semigroup based Functors.
When working with comonads you often have the
<*> portion of an
pure. This was captured in Uustalu and Vene's "Essence of Dataflow Programming"
in the form of the
ComonadZip class in the days before
Applicative. Apply provides a weaker invariant, but for the comonads used for data flow programming (found in the streams package), this invariant is preserved.
Functor ---> Apply --------> Bind | | | | v v | Applicative ---> Monad | | | v v v Alt -> Alternative -> MonadPlus
This lets us remove many of the restrictions from various monad transformers
as in many cases the binding operation or
<*> operation does not require them.
Finally, to work with these weaker structures it is beneficial to have containers
that can provide stronger guarantees about their contents, so versions of
Foldable that can be folded with just a
Semigroup are added.
|Versions [faq]||0.5.0, 0.6.0, 0.7.0, 0.7.1, 0.7.2, 0.7.3, 0.7.4, 0.7.4.1, 0.9.0, 0.9.1, 0.9.2, 0.9.3, 0.10.0, 0.10.0.1, 0.10.0.2, 0.10.0.3, 0.10.1, 0.10.3, 0.10.4, 0.10.5, 0.11|
|Dependencies||base (>=4 && <4.4), comonad (>=0.9.0 && <1.0), containers (>=0.4.0 && <0.5), semigroups (>=0.3.2 && <0.4), transformers (>=0.2.0 && <0.3) [details]|
|Copyright||Copyright (C) 2011 Edward A. Kmett|
|Author||Edward A. Kmett|
|Maintainer||Edward A. Kmett <email@example.com>|
|Uploaded||by EdwardKmett at Fri Jan 28 02:03:09 UTC 2011|
|Downloads||9576 total (197 in the last 30 days)|
|Rating||(no votes yet) [estimated by rule of succession]|
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