i'd like to run a ghci command, and capture its ouput as a haskell String, eg, to pass it on to another ghci command, or to a haskell function.
It would be possible, but needs a bit of refactoring because all the output is currently just sent to stdout. I'd go with something like your second option, but perhaps add some new syntax:
i think i've found a less disruptive approach. replace io (putStrLn output) with enqueueCommands ["let output = "++show output,"putStrLn output"] there's not always such a nice output/io separation for many commands, but we could introduce this a few commands at a time, following demand. :b Data.List .. putStrLn $ unlines $ filter (\l->"Bool" `elem` words l) $ lines output all :: (a -> Bool) -> [a] -> Bool and :: [Bool] -> Bool any :: (a -> Bool) -> [a] -> Bool elem :: (Eq a) => a -> [a] -> Bool notElem :: (Eq a) => a -> [a] -> Bool null :: [a] -> Bool or :: [Bool] -> Bool isPrefixOf :: (Eq a) => [a] -> [a] -> Bool isSuffixOf :: (Eq a) => [a] -> [a] -> Bool isInfixOf :: (Eq a) => [a] -> [a] -> Bool what worries me is that ghci's standard "it" bindings do not seem to be done this way at all, but are burried somewhere in the type-checking? also, it might be nice to introduce a GHCi qualifier, so that we could refer to GHCi.ouput and GHCi.it, in case of ambiguities? claus oh, and while i'm at it, the pretty-printing is rather less than optimal:-) zip7 :: [a] -> [b] -> [c] -> [d] -> [e] -> [f] -> [g] -> [(a, b, c, d, e, f, g)]