from-sum: Combinators for working with Maybe and Either
Provides many functions for working with Maybe and Either, including canonical fromMaybeM and fromEitherM functions. Please see README.md.
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- from-sum-0.2.3.0.tar.gz [browse] (Cabal source package)
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| Versions [RSS] | 0.1.0.0, 0.1.1.0, 0.1.2.0, 0.2.0.0, 0.2.1.0, 0.2.2.0, 0.2.3.0 |
|---|---|
| Change log | CHANGELOG.md |
| Dependencies | base (>=4.6 && <5), transformers [details] |
| License | BSD-3-Clause |
| Copyright | 2016-2019 Dennis Gosnell |
| Author | Dennis Gosnell |
| Maintainer | cdep.illabout@gmail.com |
| Category | Control |
| Home page | https://github.com/cdepillabout/from-sum |
| Source repo | head: git clone git@github.com:cdepillabout/from-sum.git |
| Uploaded | by cdepillabout at 2020-01-25T08:03:15Z |
| Distributions | Debian:0.2.3.0, LTSHaskell:0.2.3.0, NixOS:0.2.3.0, Stackage:0.2.3.0 |
| Reverse Dependencies | 3 direct, 2 indirect [details] |
| Downloads | 5561 total (20 in the last 30 days) |
| Rating | 2.0 (votes: 1) [estimated by Bayesian average] |
| Your Rating | |
| Status | Docs available [build log] Last success reported on 2020-01-25 [all 1 reports] |
Readme for from-sum-0.2.3.0
[back to package description]Control.FromSum
This Haskell module exports the fromEitherM and fromMaybeM convenience
functions.
fromMaybeM :: m a -> Maybe a -> m a
fromEitherM :: (e -> m a) -> Either e a -> m a
fromEitherM leftAction eitherValue is the same as either leftAction pure eitherValue.
fromMaybeM nothingAction maybeValue is the same as maybe nothingAction pure maybeValue.
Usage
>>> import Control.FromSum (fromEitherM, fromMaybeM)
>>> fromMaybeM [] $ Just 5
[5]
>>> fromMaybeM [] Nothing
[]
>>> fromEitherM (\s -> [length s]) $ Right 5
[5]
>>> fromEitherM (\s -> [length s]) $ Left "foo"
[3]