| So, the fold/build rule is being applied even if you run GHC with
| -fno-foldr-build-on. I RTFSed, and it appears that the only place in
GHC
| where the -ffoldr-build-on command-line option is looked at is in
| DsListComp.lhs.
|
| In the flag reference in the manual, the effect of
Bugs item #759910, was opened at 2003-06-24 16:14
Message generated for change (Comment added) made by simonpj
You can respond by visiting:
https://sourceforge.net/tracker/?func=detailatid=108032aid=759910group_id=8032
Category: Compiler
Group: None
Status: Closed
Resolution: Wont Fix
Priority:
As far as I can tell, trying to reify any declaration, even one as simple
as
x :: ()
x = ()
will result in a message similar to
ghc-6.0: panic! (the `impossible' happened, GHC version 6.0):
dsReify reifyDecl Minimal.x {- v rNZ -}
This is using the gentoo-packaged 6.0 release.
Abe
| -farrows
|
| Is this switch documented somewhere? I looked through the docs in the
| latest CVS version of GHC and couldn't find anything about it ...
Not yet: I only put it in this week! And it's not documented yet.
There are some examples, though
in
On Wed, 25 Jun 2003 10:18:17 +0100
Alastair Reid [EMAIL PROTECTED] wrote:
| It is sad that the usage of libraries containing polymorphic code
| [...]
| seems to imply runtime overheads, by preventing specialisation.
I agree that it is sad. The only way around it is to ship libraries
Some thoughts on Enum, Bounded, and [ x .. y ] notation.
Sometimes I want to write
x :: Foo - [ .. ]
that is, an enumeration with both implicit lower and upper bound.
This is useful if the type is both an instance of Enum and Bounded.
Example: in module Foo, you have
data Foo = A | B | C
PS: and enumFromThenTo should just be removed, alongside n+k patterns :-)
Even though enumFromThenTo is useful for Integral types and Rational?
[1,3 ..]
[0,1/2 .. 10] :: [Rational]
The only problems with enumFromThenTo come from providing Float and Double
instances (and are the same
Announcing the release of buddha version 0.8
www.cs.mu.oz.au/~bjpop/buddha
Buddha is a declarative debugger for Haskell 98. It is based on program
transformation and relies on GHC version 5.04 or greater (but not version 6
yet). It also needs GHC's
CALL FOR PAPERS
Special Issue of Theory and Practice of Logic Programming on
Multiparadigm Languages and Constraint Programming
Guest Editors: Moreno Falaschi and Michael Maher
Following up on a series of 11 workshops (WFLP) on multiparadigm
languages and constraint programming, the journal on
Hi!
Can somebody explain to me why ghc/hugs fails to compile the following
Haskell program? As long as MyInt is not an instance of Num the
compilations should succed... but it don't. :-( Why?
$ cat multi.hs
data MyInt = MyInt Int deriving Show
class Op_plus a b where
plus :: a - b - Int
Johannes Waldmann [EMAIL PROTECTED] writes:
x :: Foo - [ .. ]
A related point: the Haskell definition states that
For any type that is an instance of class Bounded as well as
Enum, the following should hold:
enumFrom and enumFromThen should be defined with an implicit bound, thus:
instance Op_plus MyInt MyInt where
instance (Num a) = Op_plus a MyInt where
instance (Num a) = Op_plus MyInt a where
[..]
Overlapping instance declarations:
multi.hs:9: Op_plus a MyInt
multi.hs:12: Op_plus MyInt a
Failed, modules loaded: none.
The GHC manual talks about this at:
| instance (Num a) = Op_plus a MyInt where
| i `plus` (MyInt b) = i + b
Remember that b is of type Int, but you also say that i is
of any Num type. This clashes, since + requires both if its
arguments to hve the same types.
/K
___
Haskell
Hi!
Koen Claessen wrote:
| instance (Num a) = Op_plus a MyInt where
| i `plus` (MyInt b) = i + b
Remember that b is of type Int, but you also say that i is
of any Num type. This clashes, since + requires both if its
arguments to hve the same types.
You are right! I did't notice that error.
Hi!
Keith Wansbrough wrote:
instance Op_plus MyInt MyInt where
instance (Num a) = Op_plus a MyInt where
instance (Num a) = Op_plus MyInt a where
[..]
Overlapping instance declarations:
multi.hs:9: Op_plus a MyInt
multi.hs:12: Op_plus MyInt a
Failed, modules loaded: none.
The GHC manual talks
I'm not sure this is really necessary (at least syntax-wise).
We can do something like:
data T a
class Trait a where { trait :: T a - Int }
instance Trait Int where { trait _ = 0 }
instance Trait Char where { trait _ = 1 }
As far as I can tell with the various --ddump-* flags, the
Hi
I did a Web application for the visualization of the type inference process for
the Simple Type System and pure ML. You can play with it at:
http://www.ncc.up.pt/typetool
I think it can be useful to Haskell programmers.
Comments are welcome,
Best regards
Hugo Simões
G'day all.
On Wed, Jun 25, 2003 at 08:48:12AM -0700, Hal Daume wrote:
I'm not sure this is really necessary (at least syntax-wise).
Well, of course, no extension is absolutely necessary in a Turing-hard
language. :-)
For the record, here are a couple of other solutions which avoid the
Hello,
I've been having a little trouble writing a module that waits for and
handles IO events, e.g. by reading from a pipe. It seemed natural to
use some form of callbacks here, though that may very well be the
wrong approach. I'd be happy to hear of alternatives.
Anyway, I got a callback-based
On Monday, June 23, 2003, at 02:11 AM, Ashley Yakeley wrote:
I wrote:
Does anyone else use Project Builder with Haskell? Once you fiddle
around with it a bit, it seems to work OK with makefiles. But I
wondered
if anyone had any Haskell-specific extensions?
OK, I made some spec files for
Robert Vollmert writes:
| Hello,
|
| I've been having a little trouble writing a module that waits for and
| handles IO events, e.g. by reading from a pipe. It seemed natural to
| use some form of callbacks here, though that may very well be the
| wrong approach. I'd be happy to hear of
At 2003-06-25 11:51, Andre Pang wrote:
Hi Ashley, I guess you've heard of the announcements of the new Apple
IDE announced at WWDC recently (Xcode). I'm at WWDC right now, and
I'll do my best to talk to the Apple engineers there to make sure that
all the infrastructure is in place to be able
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