Hi all,<br>Is there a datatype in Haskell that can be used to represent only quantities &gt;= 0?  I got bitten by a bug because I forgot to reject an amount that was below zero after applying a decrementing operator. A simple unit test would have caught this, but I was wondering if there was some way of getting the type system to ensure this.<br>
<br>thanks ...<br>-deech<br>