[Haskell-cafe] Reader monad

[Michael Lazarev]

2010/12/29 michael rice <nowgate at yahoo.com>
>
> From the docs (and tuts) newtype creates a new type out of an existing
type
> and gives a single constructor for doing so.
>
> what is the existing type?


Michael, you may want to see this section:
http://learnyouahaskell.com/functors-applicative-functors-and-monoids#the-newtype-keyword
and also section titled "type vs. newtype vs. data" below. It has good
explanation why there is
at least three keywords in Haskell to define types, and which of them do
what. And how they do it.