Simon Marlow wrote:
On 20/10/2009 14:54, Ralph Crawford wrote:
So far so good. This is what I want to see - a listing like this for every (interpreted of course) line of haskell code that runs, all the way to the end. Since this is a very large program, at this point I started pasting this to the terminal - 4 steps at a time...
:step :step :step :step
This gave me the listing I wanted. But after a certain point, it inevitably fails with a core dump, and what I capture from the screen is garbled up to that point anyway. I'm hoping there's a simpler way to do this. Thanks for taking the time to read this.
If you get a core dump, that's obviously a bug. If you can supply us with a small program that illustrates the bug, please submit a bug report at
http://hackage.haskell.org/trac/ghc/wiki/ReportABug
As for getting a list of the evaluation steps, we don't have anything that does exactly what you want at the moment, but it probably wouldn't be hard to implement on top of the existing debugging functionality.
If you want to execute one command more times you can do it by scripting ghci. Add something like this to your ~/.ghci file: :{ let { cmdHlp _ msg longMsg "--help" = let fullMsg = if null longMsg then msg++"\n" else msg ++ ('\n':longMsg) in return $ "putStr "++show fullMsg ; cmdHlp _ msg _ "-h" = return $ "putStrLn "++show msg ; cmdHlp action _ _ args = action args } :} :{ :def * cmdHlp ( \cntCmd -> case break Data.Char.isSpace cntCmd of { ( cnt, _:cmd ) -> return $unlines $replicate (read cnt) cmd ; _ -> return "putStrLn \"usage: :* <count> <cmd>...\"" } ) ":* <count> <cmd>... -- run <cmd> <count> times" "" :} Then you can use it like this: % ghci GHCi, version 6.10.4: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer ... linking ... done. Loading package base ... linking ... done. Prelude> :* -h :* <count> <cmd>... -- run <cmd> <count> times Prelude> :* --help :* <count> <cmd>... -- run <cmd> <count> times Prelude> :* 3 :type sqrt 2 sqrt 2 :: (Floating t) => t sqrt 2 :: (Floating t) => t sqrt 2 :: (Floating t) => t Prelude> :quit Leaving GHCi. % More information about ghci scripting: http://www.haskell.org/pipermail/haskell-cafe/2007-September/032260.html More examples of how can you script ghci: http://permalink.gmane.org/gmane.comp.lang.haskell.glasgow.user/16912 Peter.