[Haskell-beginners] newtype record syntax

[Brent Yorgey]

On Wed, Jul 14, 2010 at 10:39:23AM +0100, Tom Doris wrote:
> Can someone give an explanation of the use of record syntax in newtype
> declarations that helps one understand how it's meant to be interpreted? I
> understand the "facts" according to the language definition, but I just
> don't see why this notation was used; does it have any relationship with
> records?

Yes, the reason this notation is used is that it corresponds exactly
to defining a record containing one field.  Declaring field names in a
record really just gives you some projection functions to get the
fields out (and also some pattern-matching magic); declaring a field
name in a newtype gives you a projection function to unwrap the
newtype.

Does that help?

-Brent