The documentation of monad-validate is indeed great. I didn't know about
this package before. I will add it to my list of nice Haskell libraries.
Cheers,
Daniel
Am Sa., 4. Jan. 2020 um 20:31 Uhr schrieb Alexis King : You might want to check out
https://hackage.haskell.org/package/monad-validate, which provides a
monad transformer version of a Validation-like type. You can stack it on
top of IO and do whatever you want there. Errors are collected from
multiple branches as long as you use applicative operations where possible,
so you probably want to use ApplicativeDo. The monad laws are satisfied via
a relaxed notion of equality; see the documentation for more info. Disclaimer: I am the author of monad-validate. Alexis On Jan 4, 2020, at 08:58, Debasish Ghosh Hi - I am not an experienced Haskell programmer and would like to have some
help with the following problem .. I am trying to validate a bunch of inputs and found the package
Data.Validation. I am also using Data.Time for date and time. I have a
function like this .. validateOpenDate :: ZonedTime -> Validation [String] ZonedTime It's supposed to validate a date for which I need to fetch the current
date and time. I can do that with getZonedTime :: IO ZonedTime. I want to
check if the current time is less than the date time I pass to the function
and return an appropriate Validation. The question is how do I lift the result from IO into the Validation ? Or
is there any alternative strategy that I should consider for this
validation ? I have a number of other validations which follow the same
strategy but don't have the IO. My final goal is to be able to compose all
these validations applicatively to prepare a final ADT in a smart
constructor. Any help will be appreciated .. regards. --
Debasish Ghosh _______________________________________________
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