[Haskell-cafe] Which is the most "hackable" compiler?

[MarLinn]

So I have some crazy ideas for language extensions/reinterpretations and 
ways I might try to implement them. But ghc is a complex beast and my 
crazy ideas have too many interrelationships for a noob like me to try 
to bold them onto it. After all, I have never worked on ghc - or any 
compiler for that matter. I did look at the code, but I reckon maybe I 
should gather some experience first before diving into that one. It 
would be even worse to offload my ideas onto someone else before I at 
least tried them and got some feedback. No fun for anyone.

But of course I don't want to start from scratch. As fun as that could 
be, there's no need to reinvent all the wheels just for a different 
axle. And I hear rumors that there are other Haskell compilers out 
there, even if most of them live in the shadow/slipstream of their 
brother. Alas, I don't have any idea what their statuses and 
philosophies are.

So maybe you can help me here: Have you experienced any of the 
alternative compilers as especially easy for a newcomer to pick up and 
play around with? If it helps, I would be satisfied with plain 
Haskell2010 or even Haskell 98, although some GADT and/or TypeFamilies 
code to butcher would be nice, too. The ideas are mostly about larger 
scale structures like whole functions. One representative example idea 
is "Could it help the implementation - and does it even make sense - to 
view a module as just a weirdly written zero parameter type class?" As I 
said: crazy ideas.

I'm thankful for any thoughts and ideas.


MarLinn