[Haskell-cafe] Array and Ix for custom Graph ADT

[Daniel Fischer]

On Sunday 14 August 2011, 00:41:33, Mark Spezzano wrote:
> Hi Antoine,
> 
> The first Int field is a unique index, beginning at 1 and increasing by
> 1 for each unique Node. 

Then you could use that for indexing, assuming the Ord instance matches.

range (MyNode x _ _ _, MyNode y _ _ _) = [x .. y]
index (MyNode x _ _ _, MyNode y _ _ _) (MyNode z _ _ _)
  | x <= z && z <= y = z-x
  | otherwise = error ("Index out of range: " ++ show z)

etc.

> The second [Int] field is just a list of random
> numbers associated with that node.
> 
> Mark