Hi John,
Do you use jhc when you develop jhc? I.e., does it compile itself. For me, this is the litmus test of when a compiler has become usable. I mean, if even the developers of a compiler don't use it themselves, why should anyone else? :)
Well, this touches on another issue, and that is that jhc is a native cross-compiler. It never behaves differently if compiled by another haskell compiler or is compiled on an alternate platform. There is never a need to 'bootstrap' it, once you have jhc running anywhere then it is as good as it would be if it is running everywhere. So to me, self-hosting has never been a big issue as it doesn't provide any direct "material" benefit. My time is better spent implementing more extensions or improving the back end.
I think you might have missed Lennart's point. It's fair to say you do a lot of Haskell development work while writing a Haskell compiler. If you aren't using your compiler for your development work (in particular for your compiler) then anyone trying to use it is likely to bump in to problems. It's not that there are technical advantages of self-compilation, but it is a good statement of faith from the compiler author. Anyway, I think the Haskell community needs more compilers, so I wish you lots of luck with JHC! Thanks, Neil