Re: [Haskell-cafe] How to make boolean logic with IO Monad more expressive?

Cool. Thanks. On Mon, May 27, 2019 at 5:10 PM Viktor Dukhovni wrote:

...

On May 27, 2019, at 1:07 AM, Magicloud Magiclouds wrote:

``` status <- ioOperation -- IO-ed anyway return $ pureComputing || (status && pure2) ```

With two helpers:

(<&&>) :: IO Bool -> IO Bool -> IO Bool (<&&>) ma mb = ma >>= (\a -> if not a then return False else mb)

(<||>) :: IO Bool -> IO Bool -> IO Bool (<||>) ma mb = ma >>= (\a -> if a then return True else mb)

you'd write:

pure preComputing <||> (ioOperation <&&> pure pure2)

You could even define suitable fixity to make <&&> have higher precedence than <||> and not need any parentheses.

-- Viktor.

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