This week, at work, I've been attending a workshop which is concerned with writing (actually rewriting) a domain specific language that we've been using. Although I've only known Haskell for four months, I can see that it's infected my brain, since I kept seeing Haskell solutions to all sorts of problems that were coming up. This DSL was written by two demon programmers in C. They've made many ad-hoc choices which look rather ugly to me. Even worse, they've invented a very primitive type system which would only be checked at run time. This looks particularly bad since the applications that we'd be running are very large parallel computations. I would like to make a try at writing an alternative based on Haskell, even though there's probably little chance that I could get it adopted (since no-one else here is familiar with functional programs, etc.). However, there is one issue that I'd like to address. I was looking at http://donsbot.wordpress.com/2007/03/10/practical-haskell-shell-scripting-wi... gave a very nice presentation of a domain specific language for shell scripts. One point that was made that commands were implemented as functions, and privileged commands (i.e. those which needed root privileges) were produced a result with a separate type, so that type checking would give a compile time error if you didn't execute it via the priv combinator. But, the error messages given by ghc would be rather incomprehensible to someone who wasn't familiar with Haskell (and maybe even to someone who was!). Has anyone looked into something that would filter the error messages of put out by GHC and rewrite them into something more domain specific? Victor