Readline on Windows?
Hi, Compiling the following program (Bug.hs): module Main where import System.Console.Readline main = do ms - readline Hi print ms Using GHC 6.2.2 on Windows XP, using the command line: ghc --make Bug -o bug Produces the following message: Chasing modules from: Bug Compiling Main ( Bug.hs, Bug.o ) Linking ... c:/ghc/ghc-6.2.2/libHSreadline.a(Readline__96.o)(.text+0xaa):ghc11748.hc: undefined reference to `readline' Tried linking by hand (not using --make), specifying -package readline, specifying -lreadline; nothing worked. /Koen ___ Glasgow-haskell-bugs mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Derivable type classes bug?
Hi,
Take a look at the following program, making use of
derivable type classes.
module Bug where
import Data.Generics
class Foo a where
foo :: a - Int
foo{| Unit |}_ = 1
foo{| a :*: b |} _ = 2
foo{| a :+: b |} _ = 3
instance Foo [a]
GHC 6.2.2 produces the following error message:
Bug.hs:12:
Could not deduce (Foo a) from the context (Foo [a])
arising from use of `foo' at Bug.hs:12
Why is the context needed? 'foo' is not a recursive
function?
I guess it is because the default declaration is split up
into several instances:
instance Foo Unit where
foo _ = 1
instance (Foo a, Foo b) = Foo (a :*: b) where
foo _ = 2
instance (Foo a, Foo b) = Foo (a :+: b) where
foo _ = 3
Why not generating:
instance Foo Unit where
foo _ = 1
instance Foo (a :*: b) where
foo _ = 2
instance Foo (a :+: b) where
foo _ = 3
when the context is not needed?
(My motivation is: I have a class like this:
class Arbitrary a = Shrink a where
shrinkSub :: a - [a]
shrinkSub{| ... |} = ... shrink ...
The definition of shrinkSub is not recursive, it calls a
function 'shrink' from the Arbitrary class instead.)
Regards,
/Koen
PS. Has the implementation of Generics changed from some
earlier compiler version (GHC 5.xx)? I have code lying
around that I am almost certain of used to compile with an
earlier version of GHC (that I do not have access to
anymore).
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[ ghc-Bugs-1069656 ] ghc-ghci inconsisteny
Bugs item #1069656, was opened at 2004-11-19 19:57 Message generated for change (Settings changed) made by simonmar You can respond by visiting: https://sourceforge.net/tracker/?func=detailatid=108032aid=1069656group_id=8032 Category: None Group: None Status: Closed Resolution: None Priority: 5 Submitted By: Nightmare (goronsf) Assigned to: Nobody/Anonymous (nobody) Summary: ghc-ghci inconsisteny Initial Comment: The following program has different semantics in ghc and ghci. main = do putStrLn something putStr something else It's the linebuffering. NoLineBuffering should be used on expressions without side-effects. So 5*5 should print immediately, and do putStrLn something should behave the same in both applications. How doesn't matter that much to me, but they should be the same. -- Comment By: Simon Marlow (simonmar) Date: 2004-11-22 13:30 Message: Logged In: YES user_id=48280 Buffering of the standard handles does indeed differ in GHCi compared to GHC. The behaviour is a compromise: you don't want NoBuffering by default for stdout in a compiled program, because it would be too slow. You probably *do* want NoBuffering in an interactive environment, however, because you want interactivity. So, unless we hear from lots of people who want this to change, it'll stay as is. -- You can respond by visiting: https://sourceforge.net/tracker/?func=detailatid=108032aid=1069656group_id=8032 ___ Glasgow-haskell-bugs mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
RE: Derivable type classes bug?
Yes, you guessed right. Your generic class declaration gives rise to
instance declarations like
| instance (Foo a, Foo b) = Foo (a :*: b) where
| foo _ = 2
You suggest that it could be cleverer about guessing the context for the
instance decl, and that would make sense. But this'd then be the *only*
time that the context of an instance decl was inferred, rather than
provided. So (a) that's unusual (needs explanation etc), and (b) it'd
require some jiggling in the compiler, which is currently set up for
checking instance decls only.
An alternative, I guess, would be to ask the programmer to supply the
context for the instance decls. But it's hard to see good syntax. Were
would the context go in the class decl?
Another alternative could be for the programmer to give the
separated-out instance declarations himself, rather than having them
grouped in the class decl. But we'd still need some way to signal that
the method should be generated generically. Something like
class Foo a where
foo :: a - Int
generic foo -- New keyword
instance Foo Unit where ...
instance Foo (a :+: b) where ...
etc
Signalling generic-ness like this could even allow generic-ness on a
method-by-method basis. Kind of like specifying the default method. I
don't want to eat another keyword, though. And somehow it'd be better
if the same signal happened for the current case. But
class Foo a where
foo :: a - Int
generic foo
foo {| Unit |} = ...
seems rather heavy.
So the possibilities are:
(A). Infer the instance context.
(B). Somehow specify the instance contexts in the class decl
(C). Optionally, give separate instances for Unit, :+: etc, plus a
signal
in the class decl the default method is generic. Syntax?
I think my preferences would go (C), (A), (B); if we could agree a
syntax for (C).
Does anyone else have a (somewhat informed) opinion?
Simon
| -Original Message-
| From: [EMAIL PROTECTED]
[mailto:glasgow-haskell-bugs-
| [EMAIL PROTECTED] On Behalf Of Koen Claessen
| Sent: 16 November 2004 17:17
| To: [EMAIL PROTECTED]
| Subject: Derivable type classes bug?
|
| Hi,
|
| Take a look at the following program, making use of
| derivable type classes.
|
|
| module Bug where
|
| import Data.Generics
|
| class Foo a where
| foo :: a - Int
| foo{| Unit |}_ = 1
| foo{| a :*: b |} _ = 2
| foo{| a :+: b |} _ = 3
|
| instance Foo [a]
|
|
| GHC 6.2.2 produces the following error message:
|
|
| Bug.hs:12:
| Could not deduce (Foo a) from the context (Foo [a])
| arising from use of `foo' at Bug.hs:12
|
|
| Why is the context needed? 'foo' is not a recursive
| function?
|
| I guess it is because the default declaration is split up
| into several instances:
|
|
| instance Foo Unit where
| foo _ = 1
|
| instance (Foo a, Foo b) = Foo (a :*: b) where
| foo _ = 2
|
| instance (Foo a, Foo b) = Foo (a :+: b) where
| foo _ = 3
|
|
| Why not generating:
|
|
| instance Foo Unit where
| foo _ = 1
|
| instance Foo (a :*: b) where
| foo _ = 2
|
| instance Foo (a :+: b) where
| foo _ = 3
|
|
| when the context is not needed?
|
| (My motivation is: I have a class like this:
|
| class Arbitrary a = Shrink a where
| shrinkSub :: a - [a]
| shrinkSub{| ... |} = ... shrink ...
|
| The definition of shrinkSub is not recursive, it calls a
| function 'shrink' from the Arbitrary class instead.)
|
| Regards,
| /Koen
|
| PS. Has the implementation of Generics changed from some
| earlier compiler version (GHC 5.xx)? I have code lying
| around that I am almost certain of used to compile with an
| earlier version of GHC (that I do not have access to
| anymore).
|
|
| ___
| Glasgow-haskell-bugs mailing list
| [EMAIL PROTECTED]
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[ ghc-Bugs-1071030 ] internal error: update_fwd: unknown/strange object 12238336
Bugs item #1071030, was opened at 2004-11-22 15:45 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detailatid=108032aid=1071030group_id=8032 Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Gour (ggd) Assigned to: Nobody/Anonymous (nobody) Summary: internal error: update_fwd: unknown/strange object 12238336 Initial Comment: Hi! In my attempt to emerge i.e. compile gtk2hs on amd64 arch, I've encountered the following problem: [..] ../c2hs/c2hs -C-D__signed=signed -C-D__GLASGOW_HASKELL__=602 +RTS -H180m -M350m-RTS -C-I/usr/include/glib-2.0 -C-I//usr/lib/glib-2.0/include -C-I/usr/include/gtk-2.0 -C-I//usr/lib/gtk-2.0/include -C-I/usr/X11R6/include -C-I/usr/include/pango-1.0 -C-I/usr/include/freetype2 -C-I/usr/include/atk-1.0 -iabstract:buttons:display:entry:general:layout:menuComboToolbar:misc:multiline:ornaments:scrolling:selectors:treeList:windows:gdk:glib:pango:../compat:embedding -o : gtk/gtk.h general/Hierarchy.chs general/Signal.chs glib/GValue.chs glib/GList.chs glib/GObject.chs pango/PangoTypes.chs treeList/TreeModel.chs treeList/TreeViewColumn.chs multiline/TextIter.chs gdk/Region.chs abstract/Bin.chs abstract/Box.chs abstract/ButtonBox.chs abstract/Container.chs abstract/FileChooser.chs abstract/Misc.chs abstract/Object.chs abstract/Paned.chs abstract/Range.chs abstract/Scale.chs abstract/Widget.chs buttons/Button.chs buttons/CheckButton.chs buttons/RadioButton.chs buttons/ToggleButton.chs display/AccelLabel.chs display/Image.chs display/Label.chs display/ProgressBar.chs display/Statusbar.chs entry/Editable.chs entry/Entry.chs entry/EntryCompletion.chs entry/HScale.chs entry/SpinButton.chs entry/VScale.chs general/Enums.chs general/General.chs general/IconFactory.chs general/Style.chs layout/Alignment.chs layout/AspectFrame.chs layout/Expander.chs layout/Fixed.chs layout/HBox.chs layout/HButtonBox.chs layout/HPaned.chs layout/Layout.chs layout/Notebook.chs layout/Table.chs layout/VBox.chs layout/VButtonBox.chs layout/VPaned.chs menuComboToolbar/CheckMenuItem.chs menuComboToolbar/ComboBox.chs menuComboToolbar/ComboBoxEntry.chs menuComboToolbar/Combo.chs menuComboToolbar/ImageMenuItem.chs menuComboToolbar/MenuBar.chs menuComboToolbar/Menu.chs menuComboToolbar/MenuItem.chs menuComboToolbar/MenuShell.chs menuComboToolbar/OptionMenu.chs menuComboToolbar/RadioMenuItem.chs menuComboToolbar/TearoffMenuItem.chs menuComboToolbar/Toolbar.chs menuComboToolbar/ToolItem.chs misc/Adjustment.chs misc/Calendar.chs misc/DrawingArea.chs misc/EventBox.chs misc/FileChooserWidget.chs misc/GArrow.chs misc/HandleBox.chs misc/SizeGroup.chs misc/Tooltips.chs misc/Viewport.chs multiline/TextBuffer.chs multiline/TextMark.chs multiline/TextTag.chs multiline/TextTagTable.chs multiline/TextView.chs ornaments/Frame.chs ornaments/HSeparator.chs ornaments/VSeparator.chs scrolling/HScrollbar.chs scrolling/ScrolledWindow.chs scrolling/VScrollbar.chs selectors/ColorSelection.chs selectors/ColorSelectionDialog.chs selectors/FontSelection.chs selectors/FontSelectionDialog.chs treeList/CellRendererPixbuf.chs treeList/CellRendererText.chs treeList/CellRendererToggle.chs treeList/ListStore.chs treeList/TreeModelSort.chs treeList/TreeSelection.chs treeList/TreeStore.chs treeList/TreeView.chs windows/Dialog.chs windows/FileChooserDialog.chs windows/FileSel.chs windows/Window.chs gdk/Drawable.chs gdk/GC.chs gdk/Gdk.chs gdk/GdkEnums.chs gdk/Keys.chs gdk/Pixbuf.chs glib/GError.chs glib/GType.chs glib/GValueTypes.chs pango/PangoLayout.chs pango/Rendering.chs embedding/Plug.chs embedding/Socket.chs c2hs: internal error: update_fwd: unknown/strange object 12238336 Please report this as a bug to [EMAIL PROTECTED], or http://www.sourceforge.net/projects/ghc/ /bin/sh: /bin/sed s/\(.*\)\.chs/\1.hs/: No such file or directory removing make[1]: *** [compile] Error 1 make[1]: Leaving directory `/var/tmp/portage/gtk2hs-0.9.6-r1/work/gtk2hs-0.9.6/gtk' make: *** [make-all] Error 1 I'm on Gentoo amd64 with dev-lang/ghc-6.2.2-r1. gaura-nitai gtk2hs # uname -a Linux gaura-nitai 2.6.9-gentoo-r1 #23 SMP Mon Nov 15 21:51:39 CET 2004 x86_64 AMD Athlon(tm) 64 Processor 3000+ AuthenticAMD GNU/Linux Sincerely, Gour -- You can respond by visiting: https://sourceforge.net/tracker/?func=detailatid=108032aid=1071030group_id=8032 ___ Glasgow-haskell-bugs mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
RE: Readline on Windows?
On 16 November 2004 17:16, Koen Claessen wrote: Compiling the following program (Bug.hs): module Main where import System.Console.Readline main = do ms - readline Hi print ms Using GHC 6.2.2 on Windows XP, using the command line: ghc --make Bug -o bug Produces the following message: Chasing modules from: Bug Compiling Main ( Bug.hs, Bug.o ) Linking ... c:/ghc/ghc-6.2.2/libHSreadline.a(Readline__96.o)(.text+0xaa):ghc11748.hc : undefined reference to `readline' Sigbjorn describes how to fix this bug here: http://www.haskell.org/pipermail/glasgow-haskell-users/2004-November/007 370.html I'll add the information to the FAQ. Cheers, Simon ___ Glasgow-haskell-bugs mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
