[Haskell-cafe] A very nontrivial parser

[Donald Bruce Stewart]

andrewcoppin:
> Jonathan Cast wrote:
> >On Thursday 05 July 2007, Andrew Coppin wrote:
> >  
> >>...OK, anybody have a solution that works in Haskell 98?
> >>    
> >
> >Rank-2 types are perhaps /the/ most common, widely accepted extension to 
> >Haskell 98, after the approved addendum for FFI and the draft addendum for 
> >hierarchical modules.  I would really be concerned about using them (it's 
> >certainly not like they're going to just disappear on you one day, like 
> >say functional dependencies almost certainly will).  But that's just me.
> >  
> 
> Personally, I just try to avoid *all* language extensions - mainly 
> because most of them are utterly incomprehensible. (But then, perhaps 
> that's just because they all cover extremely rare edge cases?)

Some cover edge cases, some are just useful.  What about:

    * the FFI
    * bang patterns
    * pattern guards
    * newtype deriving

Surely, fairly simple, useful. Used a lot? :-)
 
-- Don