On Sat, 11 Mar 2006, Roberto Zunino wrote:
This avoids duplicating code between Show/ShowColl .
instance ShowColl coll = Show (CollTree coll) where
show (CollNode n) = CollNode ++ showColl n
class ShowColl coll where
showColl :: coll (CollTree coll) - String
instance ShowColl []
I have a problem with defining an instance.
module CollTree where
import Data.List(intersperse)
Say, I want to define a tree structure based on lists.
I omit the data attached to the nodes here for simplicity.
data ListTree = ListNode [ListTree]
deriving Show
This is simple
Henning Thielemann wrote:
Now I have to write 'show' related code for each collection type. This
way I probably duplicate a lot of code that is already written for the
Show instances of the collections. To be honest, I use a more special
tree structure with even more special collections so
