One of the things I’m trying to learn is that once you enter IO, it’s “impossible” to leave and that I shouldn’t enter IO if I don’t need to. I have code that needs to get the current time and do some stuff with that time and use that information to calculate the due dates for the patron’s loan. Li…

The only IO you are using is getCurrentTime. You can simply add the current time as an argument to the loanBookToPatron function: loanBookToPatron :: Book -> Integer -> Date -> Patron -> Patron loanBookToPatron bk days now p = let duedate = Time.addUTCTime (fromInteger days * Time.nominalDay) n…

Using IO Safely With Heavily Stateful Problem

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arybczak November 22, 2023, 11:39am 16

Unfortunately this seems to be a common misconception. Slowness is not an inherent property of effect libraries, effectful is fast.

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Using IO Safely With Heavily Stateful Problem

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