Implement with Types, Not Your Brain

Re:Implement with Types, Not Your Brain by quickthrower2 on Tuesday June 25, 2019 @07:17PM (#20280238)

    hoistStateIntoStateT
        :: Sem (State s ': r) a
        -> S.StateT s (Sem r) a

Sorry even that'll get my brain CPU on 100% for a few minutes.

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Re:Implement with Types, Not Your Brain by lalaithion on Tuesday June 25, 2019 @07:45PM (#20280450)

This code takes a Sem monad with a State effect in it, and turns it into a StateT monad with an inner monad of Sem and al l the other effects.

I have never user Polysemy, any effects library, or type-level lists before, but I'm reasonably sure my guess is right, despite not understanding any of the code.

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Re:Implement with Types, Not Your Brain by nilkn on Tuesday June 25, 2019 @08:47PM (#20280866)

I suspect you probably just need more experience with the base language. And I don't mean that in a bad way -- Haskell is a bit of a weird language, and it's something that you'll need to spend some time with. But indeed that's a fairly standard sort of type signature that you'll process at a glance if you've used the language a fair bit.

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Re:Implement with Types, Not Your Brain by tathougies on Tuesday June 25, 2019 @08:09PM (#20280632)

Takes a Sem with a state effect and turns it into the state monad transformer over Sem with the remaining effects?

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