[Haskell-beginners] How does the Deriving being implemented in Haskell?

David Place d at vidplace.com
Tue Jun 14 15:18:10 CEST 2011

Hi, Simon.

You should look at the Data.Derive module to see how to create your own instances.

> http://hackage.haskell.org/package/derive

David Place   
Owner, Panpipes Ho! LLC
d at vidplace.com

On Jun 14, 2011, at 8:07 AM, Haisheng Wu wrote:

> Hi guys,
>   What I understanding `deriving` is Haskell automatically make a type to be a instance of a particular typeclass.
>   If that's the case, the question is How does Haskell do that underline?
>   Take code below as sample, the type Day is now an instance of Bounded.
>  data Day = Monday | Tuesday | Wednesday | Thursday | Friday | Saturday | Sunday
>             deriving (Bounded, Enum)
>   Therefore, minBound :: Day will produce Monday.
>  Just be curious how it is being implemented.
> Thanks.
> Simon
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