Haddock generated documentation for Control.Monad.Error

Simon Marlow simonmar at microsoft.com
Thu May 5 05:47:53 EDT 2005

On 05 May 2005 06:34, Sean Seefried wrote:

> When I look in the Haddock generated code at:
> http://www.haskell.org/ghc/docs/latest/html/libraries/base/
> Control.Monad.html#t%3AMonadPlus, I don't seem to find any reference
> to the IO monad being an instance of the MonadPlus class.
> But when I look at the source code in
> libraries/mtl/Control/Monad/Error.hs it clearly is.  Why is this
> happening?

The instance is defined in Control.Monad.Error, that's all.

(Haddock doesn't currently tell you which instances are exported via
which modules, and I consider this to be a bug - though I'm not exactly
sure of the best way to fix it).


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