[Hugs-users] needing some Hugs

[Anthony Clayden]

On Thu, 5 Jul 2018 at 8:29 PM, Neil Mitchell wrote:

> Hi Ant,
>

Thanks for replying Neil.


> I don't believe anyone still maintains or uses Hugs


Yes, that's what I was expecting.


- you'd be better off looking at GHC.
>

Why?

I mean seriously: if the docos for TRex are accurate, all that
non-maintenance for Hugs has still produced a better records system than
GHC has managed, in well over a decade.
GHC has some tweaks for records (FieldPuns and DisambiguateRecordFields and
friends, also now DuplicateRecordFields).
But Trex would appear to have all that covered.

Vintage ~2006 Hugs (with extensions) was very comparable to GHC (with
glasgow-exts).
There are some subtle differences in implementation of FunDeps and overlaps.
GHC's implementation is what I'd call wrong/contrary to the literature.
(SPJ's word is "bogus".)
Hugs' implementation is more along the right lines.
GHC's behaviour today is the same as 2006. Clearly it's not going to be
fixed.

GHC now has Type Families, which sometimes gives prettier code than
FunDeps/overlaps.
But no more functionality AFAICT.

GHC has GADTs -- which I've never felt much use for.

GHC has PolyKinds and DataKinds and Type-in-type, whose main effect is to
generate impenetrable error messages (even when I didn't think I was using
those extensions).
(You can achieve DataKinds in Hugs with empty data decls -- see for example
the HList paper.)

Then I'm struggling to see anything for which I'd be "better off" with GHC.
My experience from trying to contribute to the GHC design process
is that GHC is becoming more complex, more abstract, more obtuse, its
Haskell syntax is uglier (like Perl), and no more useful.

The first extension since 2006 for which I see merit is the Quantified
constraints.
(It's hard to be sure until it's released and I can get my hands on it.
 I have in mind uses that haven't appeared in the literature or Trac
testing.
 And my questions/suggestions have gone unanswered.)
Note all the nutting-out for that was in an SPJ paper in 2000.

"unanswered" seems to be a recurring issue with GHC 'maintenance' which is
why I'm questioning your "better off".
I seldom get answers to Stackoverflow q's or glasgow-users posts or cafe
bright ideas.
So thank you again for replying here.

The features I'm looking for are clearly not going to happen unless I hack
them myself.
(In particular something that was sketched in a paper in 2002.)
Hence my question here: I have a suspicion all that feature-bloat in GHC
has made it harder to hack than it was in 2006.
(And it seems it was already harder than for Hugs.)


AntC


> On Thu, Jul 5, 2018 at 12:37 AM Anthony Clayden
> <anthony_clayden at clear.net.nz> wrote:
> >
> > Is anybody still listening here?
> >
> > I see the Hugs source distro is still around - vintage 2006, and there's
> somebody curated it on github.
> >
> > I'm particularly looking for a version with TRex, but the github-curated
> version doesn't seem to include that(?)
> >
> > Can anybody comment on how easy it is to compile Hugs (on Windows),
> compared to compiling GHC? The instructions for Hugs make out it's
> reasonably easy, whereas the instructions for GHC seem to be fraught with
> gotchas. But perhaps Hugs has as many gotchas, just not documented(?)
> >
> > My impression from discussion forums when Hugs was still active, is that
> Hugs source was easier to hack if you wanted to experiment with changes to
> the language(?)
> >
> > What seems sad these days is that GHC is so monstrous and formidable,
> hardly anybody builds experimental extensions to Haskell.
> >
> > Thank you
> > AntC
> >
> > _______________________________________________
> > Hugs-Users mailing list
> > Hugs-Users at haskell.org
> > http://mail.haskell.org/cgi-bin/mailman/listinfo/hugs-users
>
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