[Haskell-beginners] Literate Haskell - capturing output

[Brent Yorgey]

On Thu, Jan 17, 2013 at 08:00:43PM +0100, Martin Drautzburg wrote:
> Hello all,
> 
> I am using literate haskell quite a lot (otherwise I don't understand my own 
> code). This works fine for the code as such. But when I give an example usage, 
> I run code snippets in ghci and copy&paste into the main document/program, 
> which turns them into "text" (and not code).
> 
> When I make changes to the program these examples tend to no longer reflect 
> the actual program.
> 
> Is there a way to automatically run examples and include them in the .lhs 
> file, preferably with the haskell prompt and everything?

This sounds nice but I don't know of any such thing.  It shouldn't be
too bad to parse a literate Haskell file with haskell-src-exts,
process some of the literate comments, and then write it back out.
Unfortunately I do not know of a nice way to capture ghci output.  You
can find an extremely hacky solution in BlogLiterately, much of which
was copied from the lhs2TeX source:

  http://hub.darcs.net/byorgey/BlogLiterately/browse/src/Text/BlogLiterately/Ghci.hs

-Brent