[Haskell-cafe] Collections

[Thomas Schilling]

On 25 jun 2007, at 20.38, Andrew Coppin wrote:

> Lennart Augustsson wrote:
>> If you don't run into graphs you are either solving very peculiar  
>> problems, or you don't recognize them when you see them.  They are  
>> everywhere.
>
> I see lots of *trees*, but no general graphs. (As in, *data*  
> structures having cycles in them. My *code* is often cyclic...)

Graphs may appear as infinity trees, you know.

data Tree = L Int | B Tree Tree deriving Show

t1 = B (L 42) (B (L 23) t1)

=> B (L 42) (B (L 23) (B (L 42) (B (L 23) (B (L 42) (B (L 23) (B (L  
42) ...