I've given up on getting a decent text editor for editing Haskell (specifically literate Haskell -- plain Haskell works fine in GEDIT).  Instead I fire up VIM and get ... a total mess.  At first I think maybe I've screwed up a whole bunch of settings or something, so I nuke everything in my home directory that begins with .vim and then, for added measure, head over to /usr/share and nuke the entire ./vim directory tree.  I then reinstall vim (from the Ubuntu Edgy archives) to get a brand new set of config files unsullied by my hands.

I still get a dog's breakfast.

A screen shot of what I'm seeing with a representative example of a .lhs file to show what I mean can be found at http://img357.imageshack.us/img357/5798/gvimexamplezv4.png.  (I've pared it down to the minimum I could find that shows the behaviour clearly.)  The problems I'm seeing are the ugly white-on-red for underlines, the lack of any kind of differentiation for keywords/operators/etc. vs. identifiers (although some punctuation is recognized, specifically curly braces), comments not being noted, etc.  Basically it looks like the Haskell is simply not being recognized at all (and, if the @saBinds@ thing is what I think it is, it looks like some latex isn't being recognized fully either).

Can anybody vim-centric please take a look at this and give me a few educated guesses as to what is happening here?  For good measure, here's the beginning of the lhaskell.vim file that comes with my vim distribution (7.0 in the Ubuntu archives).  If it's desired I can attach the whole file.  (It isn't actually all that large.)

" Vim syntax file
" Language: Haskell with literate comments, Bird style,
" TeX style and plain text surrounding
" \begin{code} \end{code} blocks
" Maintainer: Haskell Cafe mailinglist <haskell-cafe@haskell.org>
" Original Author: Arthur van Leeuwen <arthurvl@cs.uu.nl>
" Last Change: 2004 Aug 31
" Version: 1.01
"
" Thanks to Ian Lynagh for thoughtful comments on initial versions and
" for the inspiration for writing this in the first place.
"
" This style guesses as to the type of markup used in a literate haskell
" file and will highlight (La)TeX markup if it finds any
" This behaviour can be overridden, both glabally and locally using
" the lhs_markup variable or b:lhs_markup variable respectively.
"
" lhs_markup     must be set to either  tex or  none  to indicate that
"     you always want (La)TeX highlighting or no highlighting
"     must not be set to let the highlighting be guessed
" b:lhs_markup     must be set to eiterh  tex or  none  to indicate that
"     you want (La)TeX highlighting or no highlighting for
"     this particular buffer
"     must not be set to let the highlighting be guessed
"
"
" 2004 February 18: New version, based on Ian Lynagh's TeX guessing
"     lhaskell.vim, cweb.vim, tex.vim, sh.vim and fortran.vim
" 2004 February 20: Cleaned up the guessing and overriding a bit
" 2004 February 23: Cleaned up syntax highlighting for \begin{code} and
"     \end{code}, added some clarification to the attributions
"

-- Michael T. Richter <ttmrichter@gmail.com> (GoogleTalk: ttmrichter@gmail.com) It's OK to figure out murder mysteries, but you shouldn't need to figure out code. You should be able to read it. (Steve McConnell)