[Haskell-cafe] Constructor constraints

[Rich Neswold]

Hello,

I've looked through the two tutorials and the Report, but couldn't find help 
on this topic. My question is whether you can place constraints on new data 
types. For instance, I want to make a new type that is a 4 element tuple 
where each element is greater than or equal to the previous entry. Is this 
possible?

i.e.

data Category = Membership a a a a

I'd like to be able to prevent invalid Category data from being created. Any 
information would be appreciated.

-- 
Rich

AIM : rnezzy
ICQ : 174908475
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