I've had a problem using GHC exporting the constuctor (:::).
Here is a cut down version that causes the problem.
----------8<------------
module MyList (MyList(Empty, (:::))) where
data MyList a = Empty
| (MyList a) ::: (MyList a)
----------8<------------
module User where
import MyList
myLength :: MyList a -> Int
myLength Empty = 0
myLength (x ::: xs) = 1 + myLength xs
----------8<------------
When I compile with ghc 2.09:
{kurango}ghcbug>73> ghc -c MyList.hs
ghc: module version changed to 1; reason: no old .hi file
{kurango}ghcbug>74> ghc -c User.hs
User.hs:3: Interface-file parse error: line 7 toks= []
User.hs:3: Could not find valid interface file `MyList'
Compilation had errors
The problem seems to be :::.
----------8<------------
module MyList2 (MyList(Empty, (:#:))) where
data MyList a = Empty
| (MyList a) :#: (MyList a)
----------8<------------
module User2 where
import MyList2
myLength :: MyList a -> Int
myLength Empty = 0
myLength (x :#: xs) = 1 + myLength xs
----------8<------------
{kurango}ghcbug>82> ghc -c MyList2.hs
ghc: module version changed to 1; reason: no old .hi file
{kurango}ghcbug>83> ghc -c User2.hs
ghc: module version changed to 1; reason: no old .hi file
{kurango}ghcbug>84>
As far as I can tell ::: is a permitted name for a constructor. Hugs
and GHC love it. The code reading the interface files doesn't
like it much though.
Cheers,
Rock.
--
Andrew Rock -- [EMAIL PROTECTED] -- http://www.cit.gu.edu.au/~arock/
School of Computing and Information Technology
Griffith University -- Nathan, Brisbane, Queensland 4111, Australia
