extensible-effects: An Alternative to Monad Transformers

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Warnings:

This package introduces datatypes for typeclass-constrained effects, as an alternative to monad-transformer based (datatype-constrained) approach of multi-layered effects. For more information, see the original paper at http://okmij.org/ftp/Haskell/extensible/exteff.pdf. Any help is appreciated!


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Versions 1.0, 1.1.0, 1.2.0, 1.2.1, 1.4.1, 1.5.0, 1.6.0, 1.7.1, 1.7.1.0, 1.7.1.1, 1.7.1.2, 1.7.2.1, 1.8.0.0, 1.8.1.0, 1.9.0.0, 1.9.0.1, 1.9.1.0, 1.9.2.2, 1.10.0.1, 1.11.0.0, 1.11.0.1, 1.11.0.2, 1.11.0.3, 1.11.0.4, 1.11.1.0, 2.0.0.0, 2.0.0.2, 2.0.1.0, 2.1.0.0, 2.2.1.0, 2.3.0.0, 2.3.0.1, 2.4.0.0, 2.4.0.0, 2.5.0.0, 2.5.1.0, 2.5.1.2, 2.5.2.0, 2.5.3.0, 2.6.0.0, 2.6.0.1, 2.6.0.2, 2.6.0.3, 2.6.1.0, 2.6.1.1, 2.6.2.0, 2.6.3.0, 3.0.0.0, 3.1.0.0, 3.1.0.1, 3.1.0.2, 4.0.0.0, 5.0.0.0, 5.0.0.1
Change log None available
Dependencies base (>=4.7 && <4.11), transformers (>=0.3 && <0.6), transformers-base (==0.4.*) [details]
License MIT
Author Oleg Kiselyov, Amr Sabry, Cameron Swords, Ben Foppa
Maintainer suhailshergill@gmail.com
Category Control, Effect
Home page https://github.com/suhailshergill/extensible-effects
Source repo head: git clone https://github.com/suhailshergill/extensible-effects.git
Uploaded by shergill at 2018-01-03T07:45:36Z

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Readme for extensible-effects-2.4.0.0

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extensible-effects is based on the work Extensible Effects: An Alternative to Monad Transformers. Please read the paper and the followup freer paper for details. Additional explanation behind the approach can be found on Oleg's website.

Build Status Join the chat at https://gitter.im/suhailshergill/extensible-effects Stories in Ready Stories in progress

Advantages

Limitations

Current implementation only supports GHC version 7.8 and above

This is not a fundamental limitation of the design or the approach, but there is an overhead with making the code compatible across a large number of GHC versions. If this is needed, patches are welcome :)

Disadvantages

Ambiguity-Flexibility tradeoff

A useful pattern to manage the ambiguity-flexibility tradeoff is to specialize the call to the handler of effects using type application or type annotation. Examples of this pattern can be seen in Example/Test.hs.