[Haskell-cafe] ANNOUNCE: pipes-core 0.0.1

Paolo Capriotti p.capriotti at gmail.com
Sun Mar 11 14:09:25 CET 2012

> The Category law would be broken, though:
> unawait x >>> id == yield x !== unawait x

How did you get this equation? It's not even well-typed:

unawait :: a -> Pipe a b m ()
yield :: b -> Pipe a b m ()

Someone actually implemented a variation of Pipes with unawait:
(it's called 'unuse' there).

I actually agree that it might break associativity or identity, but I
don't have a counterexample in mind yet.


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