Attached below are some minor patches to the 990121 beta release
of Hugs 98 to fix the problems reported by Bernie and Carl, plus
a couple of others in a similar vein that I spotted myself. The
only effect of these is some small updates to the hugs-specific
libraries. The interpreter itself hasn't changed, so I'm not
going to make up a new release just yet.
Quick responses to some of their comments follow. Please note that
today is my last (official) day in Nottingham, so it is particularly
important that bug reports are sent to hugs-bugs and not to my
personal email address.
Carl:
| The removal of field label punning in Haskell 98 broke Pretty.lhs;
Indeed. There are libraries in the Hugs 98 distribution that
rely on features outside Haskell 98. However, it makes sense to
have as many of the libraries as possible run in Haskell 98 mode,
so this seems like a sensible change.
Bernie:
| I am using hugs as the basis for a Haskell debugger, and I use the
| HugsInternals library. I noticed that it defines the Constructor "Addr"
| and so does the Prelude.
|
| If you import HugsInternals, you get an error b/c of the overlapping
| definitions.
Hmm. I don't understand why Addr is included in the Prelude at all;
perhaps we can remove it altogether in the final release, but it will
take some time to investigate. For the time being, you will need to
import Prelude hiding (Addr)
in any module that also does an:
import HugsInternals
(or you could use qualified imports). A similar change needs to be made
to the HugsInternals library (and is included in the patch).
Carl:
| 1) The file hugs98-990121-all_tar.gz unpacks into a directory named
| hugs98-980121-all (the year is wrong).
As bug reports go, this one's pretty amusing. Apologies for the
calendar confusion; we'll get it right next time :-)
| 2) How about adding something like the following to the top-level
| Readme file:
|
| This release also includes the type system features found in
| Hugs 1.3c; see docs/WhatsNew for a description of these features.
Documentation for the new features/changes in Hugs 98 is a bit of a
problem at the moment. A problem because it doesn't exist. Thanks
for pointing it out ... we obviously need to do something about this,
but I don't just want to use the WhatsNew file as you suggested
because Hugs 1.3c and Hugs 98 do have some differences in the type
system extensions that they implement. But perhaps it should be
renamed WhatWasNew, and I should learn a lesson about choosing
good, meaningful file names.
| 3) Some of the examples in WhatsNew are wrong. ...
I've corrected the problems that you identified, except for the
one about existential types ... because the document does give
the correct syntax for Hugs 1.3c, which is the version that it
refers to throughout, and I don't want to cause even more confusion.
It does however add further pressure on us to see that the new
system is properly documented.
Thanks again for the bug reports,
Mark
diffs.uu
