[Hugs-users] Hugs98-plus-Sept2006

[dfeustel at mindspring.com]

> On Sat, Dec 09, 2006 at 09:38:37PM +0000, dfeustel at mindspring.com wrote:
> > 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>'.
> 
> You have a file called Prelude.hs containing a module Hugs.Prelude in
> your current directory.  When Hugs starts, it loads Hugs.Prelude, which
> it finds in the default path,

the 'find' command does not find a file by the name of Hugs.Prelude anywhere
in the Hugs98 tree or in /usr/local/lib/hugs, nor in the default path, as far
as I can tell. There are, þowever, 5 different instances of Prelude.hs in the
Hugs98 tree. Why is there more than 1 instance of Prelude.hs (with different
contents to boot) in Hugs98 source?

>                               and then attempts to load Prelude from
> Prelude.hs (because . is at the front of the search path).  However this
> file contains a module Hugs.Prelude, not the Prelude it was expecting,
> and initialization fails.

Initialization does not fail. Hug terminates when initialization fails.
Initialization takes a different path when it encounters Prelude.hs in
either $HOME or . directories. The alternate initialization path makes hug
work as the Haskell book describes on page 13. Where is the module Hugs.Prelude
found during hugs initialization, if not in Prelude.hs?
 
> The error message when Hugs finds a file to contain the wrong module
> could be better, though.

I agree. Perhaps some standardization of terminology would help too.

Dave