[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>

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