[Haskell-cafe] empty Array?

[Josef Svenningsson]

> It is, of course, trivial to implement this for lists.  I've run into
> a snag, however, when trying to implement this for Arrays (as in
> Data.Array) - I can't seem to find a way to represent an empty array,
> which makes implementing 'empty' and 'null' impossible.  Suggestions?
> 
Empty arrays can be achieved by having bounds where the lower bound is
greater than the upper bound. An example would be:

> empty = array (1,0) []

The function null would check the bounds to see if the lower bound is
greater than the upper bound.

HTH,

	/Josef