[Haskell-cafe] Re: [Haskell] ANNOUNCE: GHC survey results

Bernard Pope bjpop at cs.mu.OZ.AU
Thu Jun 30 06:10:38 EDT 2005


On Thu, 2005-06-30 at 10:36 +0100, Simon Peyton-Jones wrote:
>  | If anything I would like to see the Haskell community produce a
> Haskell
> | front end which was compiler neutral. That would facilitate many
> | interesting projects, and that might even help with the need to
> support
> | new extensions as they come along. There are already some candidates
> | floating around, but it seems they are not widely adopted.
> 
> Well, "ghc -c -fext-core Foo.hs" is a Haskell front end that produces
> System F code ("External Core"), in a file Foo.hcr.  I'm not sure
> whether that was what you meant.

That is one option, but it wasn't really what I meant. I was thinking of
plain old Haskell library code that implements Lexer, Parser, Desugar,
Type Inference etc. All the bits that happen at the front of a Haskell
compiler. This is what hatchet was supposed to be, and may one day
become.

I've tried in the past to pull the front end off ghc and nhc98 without
much luck. Though it looks like ghc-as-a-library might be just what the
doctor ordered. 

There is also the Programmatica project which seems to do a lot of what
I'm thinking of already. 

> However, External Core doesn't seem to have really caught on.

One problem is that different tools will want different views of the
code. External Core is probably too far away from the original source
for something like hat. 

> Only 5% said it was essential, with another 16% saying "nice to have".  

I would hazard a guess that fewer than 5% of GHC's users are writing
source transformation tools :)

> I'm sure there's room to improve the ExtCore route.

You are right, and to be honest I haven't really given much thought to
that route until now. 

Thanks for the pointer.

Cheers,
Bernie.



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