while working on a random project, I had opprotunity to write a 'parallel show' which concurrently evaluates everything needed to show a structure and lets you print succesivly refined versions as vaules are calculated and filled in. it is nice because a value that takes a long time (or perhaps forever) to evaluate at the front of your structure doesn't keep you from seeing what else is in it. I must say it has been a very useful little bit of code so thought I might share the concept and was curious if anyone else does things like this.. it works something like foo = [Right "foo", Left undefined, undefined, Right "here"] parShow (parPretty foo) >>= putStrLn => "(Right foo) (Left _|_) _|_ (Right here)" and succesive calls to parShow will fill in the _|_ values as they get evaluated. my attached implementation is rather weak (my real one is tied into a project and does wierd things with ANSI escape codes to redraw the screen as things get evaluated and handles exceptions differently) but the gist is the same. would people be interesting in me( or someone else :) ) turning this into a full fledged library? does one alreoady exist which does this? I was thinking integrating it into a real pretty printing system would be handy but might be too much work, if there were a way to reuse an existing pretty printing library without change and somehow add this capability then that would be cool. I couldn't think of a way to do it since the final 'render' routine obviously needs to be in the IO monad so the MVars can be checked again when rerendering.. John -- --------------------------------------------------------------------------- John Meacham - California Institute of Technology, Alum. - john@foo.net ---------------------------------------------------------------------------