On the fly Haskell programming?

[Stephen Milborrow]

> A much simpler approach giving essentially all the benefits would be to
> have a signal (presumable OS dependant) which causes hugs execute a reload
> of the top level module (with the current accompanying loading of any
> imported modules which have changed) upon recipt of a signal of some sort,
> then arrange for that signal to be sent upon moving the mouse cursor into
> an evaluation window in a programmable editor (eg emacs). That way you
> can...

You may want to check out the following mail which describes something
similar to your "reload on signal" idea:

http://www.mail-archive.com/hugs-users@haskell.org/msg00523.html

Instead of a signal, I modified winhugs to execute the commands in a
standard "autoload file" whenever the mod time on the file changed.
By writing to  the file in emacs you can control winhugs.  Doesn't sound
like much, but is nice in practice, especially if you are learning
Haskell and  go through the edit-run cycle hundreds of times while
deciphering inscrutable error messages :-)

The signal approach would be cleaner. And I shouldn't have used the
term "autoload" because it already means something else in winhugs.

Stephen Milborrow