[Haskell-beginners] short-circuit like Maybe monad with a difference

[Dennis Raddle]

I just tried something



evalRules :: [Rule] -> Step -> [Double]
evalRules rules step = catMaybes . takeWhile isJust . map (flip evalRule
step) $ rules

This seems to work according to my testing.



On Fri, Sep 30, 2016 at 1:32 PM, Imants Cekusins <imantc at gmail.com> wrote:

> > short-circuits the computation if it hits Nothing. However, unlike the
> way the Maybe monad works, I want to know the partial results.
> ​
> could store partial results in a State monad.. Maybe would short circuit
> but the values would stay in the State.
>
> would this work?
>
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