[Haskell-cafe] Re: Datatypes - Haskell

[Don Stewart]

ok:
> On the subject of data types, I've recently seen Haskell code using
> 	data Foo ... = Foo { ... }
> where I would have used newtype instead of data.  When is it a good
> idea to avoid newtype?

It depends what's in the ...

If its just something with the same representation as an existing type,
using a newtype makes sense. If it builds a more complicated
single-contructor type, such as many record types, then data is
required.

-- Don