FW: [Template-haskell] RE: calling fail in Q monad gives uninformativeerror message, anderror causes panic

[Mike Thomas]

Hi Simon.

I think you deserve a reply on these questions as at their heart is an 
important point which I believe remains unanswered.

Simon Peyton-Jones wrote:
> Dear Template Haskell colleagues
> 
> I sent three messages to the TH list a month ago.  Here's one of them:
> the others concerned the conversions TH.Syntax <-> HsSyn; I'll fwd them
> in the next two messages
> 
> I didn't get a single reply to any of the three.  Either the TH mailing
> list is broken, or else you are all busy with other stuff.  (After all,
> all three did ask for volunteers, in one form or another.)
> 
> Does anyone care?

I am not using TH personally due to lack of time (as with most of my 
"free time" projects for the past year or two - job, family etc, etc).

Never-the-less, I think TH is important because it explores, in the 
context of the SML family of languages and particularly non-strict 
Haskell, the equivalent of one of the more powerful features available 
in Lisp - macros.

Despite all the work you and your collaborators have done I believe that 
it remains to be seen in a large, mature project whether the methodology 
of TH is of such practical benefit to Haskell as macros have been to 
Lisp and even templates to C++.

I'm inspired particularly by the Blitz++ C++ numerical library and the 
beautiful exposition of how to compile Prolog into Common Lisp made by 
Peter Norvig in his book "Paradigms of Artificial Intelligence 
Programming: Case Studies in Common Lisp", if you need any inspiration.

I also think that TH could find uses in foreign function interface 
marshalling.

> I'm busy implementing GADTs at the moment, so TH has a
> somewhat back seat.  It'll probably stay that way unless there are some
> signs of life in the TH ranks.

This email provides nothing concrete for you, for which I apologize, but 
I hope that you and your colleagues don't drop the topic in the longer 
term as I feel you have only scratched the surface in terms of practical 
research potential.

Cheers

Mike Thomas.