October 2007 - Hugs-Bugs

:r myfile.hs does nothing
by Neil Mitchell 25 Oct '07

25 Oct '07

Hi While teaching beginners I noticed that about 5 of them made the same mistake. They were typing ":r filename.hs" to load a file, which doesn't load a file, but reloads the currently active module (the Prelude in this case). It was made worse by the fact that their file was sum.hs and contained an implementation of sum which they had to test - and the Prelude version hid their error. Is there anything that can be typed after ":r" which gives the command any effect? If not, perhaps ":r anything" should be reported to the user as a warning or an error. To compare to GHC's behaviour: GHCi Prelude> :r Ok, modules loaded: none. Prelude> :r foo.hs module does not exist Prelude> Thanks Neil

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Re: [Hugs] #59: missing and/or erroneous output in deteministic function run from WinHUGS cmd line!
by Hugs 21 Oct '07

21 Oct '07

#59: missing and/or erroneous output in deteministic function run from WinHUGS cmd line! ---------------------------------------------+------------------------------ Reporter: ettinger(a)elmgate.eclipse.co.uk | Owner: Type: defect | Status: new Priority: critical | Milestone: Component: hugs | Version: 200609 Resolution: | Keywords: inconsistent expression evaluation ---------------------------------------------+------------------------------ Comment (by guest): Test Trac email again. [http://www.seductionbase.com/ seduction] [http://www.seductionbase.com/pickuplines pickup] -- Ticket URL: <http://hackage.haskell.org/trac/hugs/ticket/59#comment:4> Hugs <http://www.haskell.org/hugs/> Hugs 98, an interpreter for Haskell

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Re: [Hugs] #29: WinHugs: $$ last value doesn't work
by Hugs 21 Oct '07

21 Oct '07

#29: WinHugs: $$ last value doesn't work -----------------------+---------------------------------------------------- Reporter: neil | Owner: neil Type: defect | Status: closed Priority: critical | Milestone: next release Component: winhugs | Version: 200605 Resolution: fixed | Keywords: -----------------------+---------------------------------------------------- Comment (by guest): Test Trac email again. [http://www.seductionbase.com/ seduction] [http://www.seductionbase.com/pickuplines pickup] -- Ticket URL: <http://hackage.haskell.org/trac/hugs/ticket/29#comment:5> Hugs <http://www.haskell.org/hugs/> Hugs 98, an interpreter for Haskell

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Re: [Hugs] #73: Sieve of Eratosthenes crashes if using "Integer" while not if using "Int"
by Hugs 21 Oct '07

21 Oct '07

#73: Sieve of Eratosthenes crashes if using "Integer" while not if using "Int" ---------------------+------------------------------------------------------ Reporter: guest | Owner: nobody Type: defect | Status: new Priority: minor | Milestone: Component: hugs | Version: 200609 Resolution: | Keywords: ---------------------+------------------------------------------------------ Comment (by guest): Test Trac email again. [http://www.seductionbase.com/ seduction] [http://www.seductionbase.com/pickuplines pickup] -- Ticket URL: <http://hackage.haskell.org/trac/hugs/ticket/73#comment:4> Hugs <http://www.haskell.org/hugs/> Hugs 98, an interpreter for Haskell

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Re: [Hugs] #78: getCh
by Hugs 17 Oct '07

17 Oct '07

#78: getCh ----------------------+----------------------------------------------------- Reporter: guest | Owner: nobody Type: defect | Status: closed Priority: minor | Milestone: Component: hugs | Version: 200609 Resolution: wontfix | Keywords: ----------------------+----------------------------------------------------- Changes (by ross): * status: new => closed * resolution: => wontfix Comment: It was a Hugs-only function, and now it's gone. You should be able to get the same effect with `hSetBuffering` and `hSetEcho` (from `System.IO`). -- Ticket URL: <http://hackage.haskell.org/trac/hugs/ticket/78#comment:1> Hugs <http://www.haskell.org/hugs/> Hugs 98, an interpreter for Haskell

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[Hugs] #79: Memory leak ?
by Hugs 17 Oct '07

17 Oct '07

#79: Memory leak ? --------------------+------------------------------------------------------- Reporter: guest | Owner: nobody Type: defect | Status: new Priority: major | Milestone: Component: hugs | Version: 200609 Keywords: | --------------------+------------------------------------------------------- Lately I've come across a most interesting error. With this code for rev: {{{ rev [] xs = xs rev (x:xs) ys = rev xs (x:ys) }}} Hugs returned: {{{ Main> rev tab1 [] ERROR - Garbage collection fails to reclaim sufficient space Main> }}} After some tests I've found out that (of course after restarting Hugs) that request to print on screen ''tab'' where the code is {{{ tab = [1..1000000] }}} will result in a same crash (ERROR - Garbage collection fails to reclaim sufficient space). Results where like this:[[BR]] {{{ . . . 246368,246369,246370,246371,246372,246373,246374,246375,246376,246377,246378,246379,246380,246381,246382,246383,246384,246385,246386,246387,246388,246389,246390,246391,246392,246393,246394,246395,246396,246397,246398,246399,246400,246401,246402,246403,246404,246405,246406,246407,246408,246409,246410 ERROR - Garbage collection fails to reclaim sufficient space Main> }}} Yet still request to simply print [1..1000000] is managed without this problem (of course after restarting Hugs). Seems like some sort of a memory leak, but in which part? After those problems occure there are problems to do much simpler thing. Example:[[BR]] {{{ Main> (length tab) `seq` "" " ERROR - Garbage collection fails to reclaim sufficient space Main> [1..100] [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23, ERROR - Garbage collection fails to reclaim sufficient space Main> }}} Looks like the constructor '..' works well because there is no problem with printing [1..n] where n > 1 000 000 but on the other hand there seem to be problems on passing such list (even shorter) to a variable ''tab''.[[BR]] 1. Is this passing blocks garbage collector from cleaning this memory once it's aloccated during printing?[[BR]] 2. Maybe it was intentional because of something I don't know. If it is, please could You explain why? [[BR]] Many thanks for Your time.[[BR]] Simon Laszczynski (bast_ian(a)poczta.onet.pl) [[BR]] PS: Forgive me my bad english. -- Ticket URL: <http://hackage.haskell.org/trac/hugs/ticket/79> Hugs <http://www.haskell.org/hugs/> Hugs 98, an interpreter for Haskell

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