EDSL done...

The expect embedded Domain Specific Language portion of my code has turned out to be quite the useful little sublanguage to flexibly write little scripts in for controlling, over various channels (ssh, telnet, local comm ports perhaps), devices.

I probably can't document too much about it here, as it's company IP, but I can tell you that building up an EDSL in Haskell is not near as difficult as I thought, at least in the case I've implemented. It's a matter of choosing the right Monad Transformer base, or writing your own (which could take a long time actually depending on how well you can wrap your head around the sequencing of the various actions you'd like to take). Also once you realize that the aggregation and sequencing of simpler actions can be used to build up more complex ones, you're pretty much golden and have learned to realize the full power of the Monad concept.

It's also one thing to see it, or even read about it, but the real eye-opening bit is when you actually implement one that's useful to you on your own. Then you almost want to beat your chest and proclaim you're the new king of the tribe.

I love a programming language that you can use to build specialized tools ,*very* quickly, that meet your immediate need.

My boss even almost threw me a curve ball on the way he thinks I should utilize this technique. Then I realized that what I'd written could most easily support the sort of idea he was after because I picked the right abstractions.

I'm very grateful that this technology even exists, as it is saving us a lot of time where I work, making progress on this sort of programming that otherwise seems a ton of work.

Haskell is definitely for the win today :-)