[Haskell-cafe] bug in all about monads tutorial
Peter Hercek
phercek at gmail.com
Sun Jan 20 07:39:04 EST 2008
Hi,
About 3 weeks ago I reported this bug to Jeff Newbern.
But I got no response - maybe I got filtered out as spam :)
Since it was not fixed I'm trying once more here. Maybe
there is somebody here who has access to the web site
http://www.haskell.org/all_about_monads and cares enough
to fix it.
On page
http://www.haskell.org/all_about_monads/html/writermonad.html
there is "listens" defined like this:
listens f m = do (a,w) <- m; return (a,f w)
... but it should be like this:
listens f m = do (a,w) <- listen m; return (a,f w)
... or maybe a less strict option (as ghc libs have it):
listens f m = do ~(a,w) <- listen m; return (a,f w)
Peter.
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