edison question

Hal Daume III hdaume@ISI.EDU
Tue, 30 Jul 2002 10:16:38 -0700 (PDT)


I'm no edison expert but it seems the problem simply is that you're using
overloaded functions and the compiler can't tell which instance you're
trying to use.  Try adding a type signature to the definition of sorted
(I'm not familiar enough with edision to know what the type is) but
something like:

  let sorted = ... :: SOMETYPEHERE

hopefully someone will provide a more complete answer soon, but since no
one has replied yet...

 - Hal


--
Hal Daume III

 "Computer science is no more about computers    | hdaume@isi.edu
  than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume

On Tue, 30 Jul 2002 paul@theV.net wrote:

> I am quite confused with the collection package provided by
> the edison library. Attached is a sample program, what I
> wanted to do is to maintain a sorted of Pair of id and time
> (sorted by time). The error I got is:
> 
> ghc -package data -package lang test.hs
> 
> test.hs:17:
>     No instance for `Collection.OrdColl c Pair'
>     arising from use of `Collection.minElem' at test.hs:17
>     in a pattern binding: Collection.minElem sorted
> 
> Actually I don't really understand what a class like
> "OrdColl c a" really means and how to use them. Please help!
> 
> Regards,
> .paul.
>