[Haskell-cafe] IntMap documentation error

Duncan Coutts duncan.coutts at worc.ox.ac.uk
Tue Feb 24 20:31:21 EST 2009

On Mon, 2009-02-23 at 17:22 -0600, Louis Wasserman wrote:
> In the documentation for Data.IntMap updateMin, a piece of example
> code both communicates incorrect intuition, and fails to even compile.
> updateMin :: (a -> a) -> IntMap a -> IntMap a
>  updateMin (\ _ -> Nothing) (fromList [(5,"a"), (3,"b")]) -- code
> straight from the docs
> <interactive>:1:49:
>    Couldn't match expected type `Maybe a'
>           against inferred type `[Char]'
>    In the expression: "a"
>    In the expression: (5, "a")
>    In the first argument of `fromList', namely `[(5, "a"), (3, "b")]'
> As a side note, the sort of operation implied by the example code was
> really what I was looking for in the documentation -- but such a
> method no longer exists in IntMap.  ::sad::
> Who do I tell this to / how do I ask to get it fixed?

Open a ticket in the ghc trac:

set the component to "libraries other". Paste in your description and if
you can, attach a darcs patch to the ticket.

More generally, to work out where to send things check the hackage page.
Most packages list a maintainer or author and some are now specifying a
bug reports url.

Currently for the containers package it's not all that helpful, it only
lists a maintainer email address as libraries at haskell.org. Though that
would also have been a place to start to get the above advice. The next
release of all the core packages will also list their bug-report urls
and these will appear on their hackage pages.


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