[Haskell-begin] data declarations

Brandon S. Allbery KF8NH allbery at ece.cmu.edu
Tue Jul 22 23:26:22 EDT 2008

On 2008 Jul 22, at 23:01, Roger Myers wrote:

> Not sure if I'm on the right track here, so as a beginner I thought  
> I'd ask on
> this list.
> I want to declare a type 'All' that consists of the of the types  
> 'Tinteger,
> Tbool, Tstring, Tarray' but I would also like to make a relationship  
> that
> Tinteger and Tbool are also the type 'Simple' and that 'Tstring' and  
> 'Tarray'
> are 'Composite' and that Mixed is then either Simpletype or Composite.
> So I can then write a function that takes a type of All and produces  
> a list of
> Mixed.

Any particular reason that All can't be represented by Mixed?  That  
would be my first cut at it (assuming I didn't need advanced type  
hackery for some reason).

brandon s. allbery [solaris,freebsd,perl,pugs,haskell] allbery at kf8nh.com
system administrator [openafs,heimdal,too many hats] allbery at ece.cmu.edu
electrical and computer engineering, carnegie mellon university    KF8NH

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