[Haskell-beginners] accessor function scope

Brandon S. Allbery KF8NH allbery at ece.cmu.edu
Tue Apr 7 13:38:16 EDT 2009

On 2009 Apr 7, at 9:15, Daniel Fischer wrote:
> Yes, they're called algebraic datatypes, but I'm not sure if a type  
> must have
> more than one constructor to qualify as such.

An ADT is any type expressible by a combination of sum and product  
types, IIRC.  Single constructor types are product types, multiple  
constructors are sums of product types.  (Note that this leaves out  
"data Nil"; that's why it's an extension.  "data Nil = Nil" is  
vacuously an ADT.)

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

-------------- next part --------------
A non-text attachment was scrubbed...
Name: PGP.sig
Type: application/pgp-signature
Size: 195 bytes
Desc: This is a digitally signed message part
Url : http://www.haskell.org/pipermail/beginners/attachments/20090407/9275ed20/PGP.bin

More information about the Beginners mailing list