User preferences lost between Hugs upgrades on Windows

[Neil Mitchell]

Hi

> well, you can't change what other people do, but you can make
> sure that Hugs doesn't steal ;)

If there are two of you, one that does steal, one that doesn't, I
might as well make the Hugs installer register GHC as the extension
handler! It's also a bit annoying to do a load of work to get around
problems in an open source program, when a much nicer solution could
be obtained by cooperation.

> - register file type handlers optionally (I think Hugs already does
>     this, but GHC doesn't?)
Hugs definately has this as an option (on by default).

> - only _add_ file type handlers, never override existing ones
>     nor change the default handler without user confirmation
Well, the user has to choose, so they have made confirmation. The way
the extension registry system works, this is quite hard! You register
an extension with a class, and then you put the available methods in
that class. It would be very rude (and fragile) to shove the methods
in someone elses class. If there is some cooperation, and agreement
before hand (i.e. GHC won't delete the common Hugs/GHC class on
uninstall etc. if there is still a Hugs entry), it can be done, but
not by one side only.

> > Have you used a recent copy of WinHugs?
>
> oops. I was sure I had, and had encountered problems with
> starting the editor (:e) on internet files which WinHugs was not
> equipped to handle (non-standard extensions, missing imports, ..).
> something like messed up temporary files paths to the downloaded
> file, which the editor couldn't find when called from WinHugs, I
> seem to recall.. - but I can't reproduce the problem with
> "Version: 20051031".

Good good :) I did rewrite all the editor code substantially for WinHugs.

> offering to call an editor via WinHugs looks nice and convenient
> when there are no editors registered, but isn't really the way to
> go otherwise, is it? There was a time when I needed to open
> Haskell files with several editors, for testing, and in any case,
> why should editor actions go via other software?

The reason editor preference should go via WinHugs, is because the
user has selected their preferred text editor in WinHugs, so at that
point WinHugs probably has a better chance of guessing which text
editor is best. If they register explicit file handlers for .hs we
should respect them however.

> why not make that "Open with WinHugs" and "Edit via WinHugs"
> and let the user decide which, if any, of these should be default?

>From what I remember, defaults in extension handlers don't work that
way :) I think it might be possible though, and I'd love to be able in
WinHugs to let the user pick "Open in GHCi" as their preferred option.

> oh, you mean I should have mentioned this earlier, as in
>
> http://www.haskell.org/pipermail/glasgow-haskell-users/2004-March/006402.html
> http://www.haskell.org/pipermail/hugs-users/2006-February/000656.html

You're not the only one:

http://article.gmane.org/gmane.comp.lang.haskell.cvs.ghc/14819/

Thanks

Neil