[Haskell-cafe] Information given by :info (Was: Some randomnewbie questions)

[Simon Marlow]

On 10 January 2005 10:26, Sebastian Sylvan wrote:

> On Mon, 10 Jan 2005 10:30:46 +0100 (MEZ), Henning Thielemann
> <iakd0 at clusterf.urz.uni-halle.de> wrote:
>> What I also would like to see is the Haddock documentation
>> string of a function printed by ":info" or some other command.
>> 
> 
> Now _that_ would be truly useful.

It's not perfect, but it's better than nothing:

:def doc (\s -> let (rvar,rmod) = break (=='.') (reverse s); var =
reverse rvar in System.Cmd.system ("mozilla
http://www.haskell.org/ghc/docs/latest/html/libraries/base/" ++ reverse
rmod ++ "html#" ++ (if (Data.Char.isUpper (head var)) then "t:" else
"v:") ++ var) >> return "")

eg.

Prelude> :doc Prelude.head

You have to use a qualified name, it only works in package base, and you
can't look up data constructors.  Any hackers out there want to try
lifting these restrictions?

Cheers,
	Simon