[Haskell-cafe] Type Directed Name Resolution
David Menendez
dave at zednenem.com
Thu Nov 11 20:37:04 EST 2010
On Thu, Nov 11, 2010 at 8:16 PM, John Lask <jvlask at hotmail.com> wrote:
> consider "length" ...
>
> I have records with the attribute length, length can be given as an Int,
> Double, Float or maybe as a constructed type "Length", length's use as a
> record selector would also clash with List.length. All these have the same
> denotation.
>
> should I then seporate into int_length, float_length, or use rec1_length,
> rec2_length etc etc...
class Lengthy a where
type LengthType a
length :: a -> LengthType a
This extends easily to lenses if you want setters.
> This is easily handled in C, Pascal, PL/1, Cobol why not in Haskell ?
By this argument, Haskell should provide global mutable state and
allow side-effects universally.
--
Dave Menendez <dave at zednenem.com>
<http://www.eyrie.org/~zednenem/>
More information about the Haskell-Cafe
mailing list