[Hat] Hat bug report: Ambiguous occurrence `List'

[Fergus Henderson]

On 23-Jun-2004, Malcolm Wallace <Malcolm.Wallace at cs.york.ac.uk> wrote:
> > The main problem here seems to be that Hat doesn't support the "Data.Word" module.
> > Is there any simple work-around?  I'm not particularly interested in tracing
> > that module.
> 
> I have just checked into CVS a tracing version of Data.Word.

Thanks!

> It compiles, but I haven't tested it.  Currently it provides instances of
>     Eq, Ord, Bounded, Num, Enum, Read, Show
> but omits instances of
>     Real, Integral, Ix
> because of tedious errors I haven't tracked down.  If you need those
> instances, I'll look into it further.

It turns out that I do need at least the Integral instances.

I tried uncommenting those, and got an error about "fromRational" being
undeclared.  I then tried adding "import Prelude(fromRational)" to
src/hatlib/Data/Word.hs, but that didn't work. I ran into the following
problem:

 | bash$ make
 | cd src/hatlib;         make HC=ghc6 all
 | make[1]: Entering directory `/home/fjh007/hat/cvs/hat/src/hatlib'
 | /home/fjh007/hat/cvs/hat/script/hat-trans -P. -I. -trusted -prelude -D__GLASGOW_HASKELL__=620 Data/Word.hs
 | 
 | Fail: AuxLabelAST.letVar: == not let-bound in env

The build continued a little longer,

 | ghc6 -package-name hat -fglasgow-exts  -package lang -package base -fno-warn-overlapping-patterns -fno-warn-missing-methods -i/home/fjh007/hat/cvs/hat/targets/ix86-Linux/obj/hatlib/ghc6 -I. -I/home/fjh007/hat/cvs/hat/include  '-#include "hat-c.h"' -c -o /home/fjh007/hat/cvs/hat/targets/ix86-Linux/obj/hatlib/ghc6/Hat/Data/Word.o Hat/Data/Word.hs
 | 
 | Hat/Data/Word.hs:1:
 |     The main function `main' is not defined in module `Main'
 | make[1]: *** [/home/fjh007/hat/cvs/hat/targets/ix86-Linux/obj/hatlib/ghc6/Hat/Data/Word.o] Error 1

but I think the first error message is the one that is really causing the problem.

Cheers,
	Fergus.

-- 
Fergus J. Henderson                 |  "I have always known that the pursuit
Galois Connections, Inc.            |  of excellence is a lethal habit"
Phone: +1 503 626 6616              |     -- the last words of T. S. Garp.
-------------- next part --------------
Index: src/hatlib/Data/Word.hs
===================================================================
RCS file: /cvs/hat/src/hatlib/Data/Word.hs,v
retrieving revision 1.2
diff -u -r1.2 Word.hs
--- src/hatlib/Data/Word.hs	23 Jun 2004 14:27:07 -0000	1.2
+++ src/hatlib/Data/Word.hs	29 Jun 2004 00:27:17 -0000
@@ -8,6 +8,7 @@
 import qualified TraceOrigData.Word
 import TraceOrigIx
 import Ix
+import Prelude(fromRational)
 
 #define INSTANCE_EQ(T)		\
 ; foreign import haskell "Prelude.==" eq/**/T :: T -> T -> Bool \
@@ -113,7 +114,6 @@
 INSTANCE_BOUNDED(Word32)
 INSTANCE_BOUNDED(Word64)
 
-{-
 INSTANCE_REAL(Word)
 INSTANCE_REAL(Word8)
 INSTANCE_REAL(Word16)
@@ -126,6 +126,7 @@
 INSTANCE_INTEGRAL(Word32)
 INSTANCE_INTEGRAL(Word64)
 
+{-
 INSTANCE_IX(Word)
 INSTANCE_IX(Word8)
 INSTANCE_IX(Word16)