Daniel Carrera wrote:
Magnus Therning wrote:
aditya siram wrote:
Hi all, Is there a datatype in Haskell that can be used to represent only quantities >= 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.
Maybe Word32 (or one of it's siblings) would do? It's basically the same as 'unsigned int' in C, so it can under- and over-flow.
What's under-flow?
Negative overflow:
let one = 1 :: Word8 one - 2 255
/M -- Magnus Therning (OpenPGP: 0xAB4DFBA4) magnus＠therning．org Jabber: magnus＠therning．org http://therning.org/magnus identi.ca|twitter: magthe