Re: unordered stuff in the parser combinator

Geoffrey Alan Washburn wrote:
> Matt Hellige wrote:
>> It's possible to write a permutation parser combinator in Haskell.
>> Here is the key:
>>   http://citeseer.ist.psu.edu/451549.html
>> It's not complex, but I haven't read the paper in depth, so I don't
>> know if it transfers trivially to Scala.
> 
> Skimming the paper indicates that it requires higher-rank polymorphism 
> (which *is not* the same as higher-kinded polymorphism, which Scala does 
> provide).  So a trivial translation is out of the question.  It may be 
> possible, but it will require some cleverness.

Nope, I misread it.  They were just using Haskell's forall quantifier 
notation for what is really an existential type.  This should be 
straightforward then.