[Hugs-users] Hugs98-plus-Sept2006

[dfeustel at mindspring.com]

> On Sat, Dec 09, 2006 at 07:20:41PM +0000, dfeustel at mindspring.com wrote:
> > I have now determined to my satisfaction that Hugs98-plus-Sept2006 has
> > initialization problems concerning Prelude.hs and the use of the -P option.
> > These problems may be peculiar to the port of Hugs to OpenBSD. In any event
> > I have started poking around with gdb to try to figure out what's going on.
> > (I actually can induce hugs to recognize the various prim functions that
> > I initially had trouble with, but it's clear that Prelude processing does
> > not work exactly as documented.)
> 
> I guess that you're trying to add /usr/lib/hugs/packages/hugsbase/Hugs
> to the search path.

The path above is part of the default search path for Prelude.hs.
What I have discovered is that þugs, invoked with no arguments,
initializes itself differently depending upon the presence or absence
of Prelude.hs in the $HOME directory.  With Prelude.hs *not* present
in $HOME, I get the behavior described in the original post. When
Prelude.hs *is* present in $HOME, then an error re loading Prelude.hs
is reported, and primMinInt/primMaxInt/primMaxChar all work and the
prompt is 'Hugs.Prelude>'.

>                      This isn't supposed to work, because that directory
> isn't the root of a module hierarchy: each file X.hs in there contains
> a module Hugs.X, not X.  It's the parent of that directory that is a
> module hierarchy, and it's already in the search path.
> 
> If you're determined to use these prim* functions (though you shouldn't
> because they're internal, and there are Haskell 98 equivalents of each
> of them), you can approximate the pre-2002 Hugs Prelude with
> 
> 	Hugs> :m Hugs.Prelude
> 	Hugs.Prelude> primMaxInt
> 	2147483647
> 
> There are no guarantees that it will work in the future, though.