[Haskell-cafe] Maybe a, The Rationale

PR Stanley prstanley at ntlworld.com
Tue May 13 17:35:16 EDT 2008

>         Paul:   What is the underlying rationale for the Maybe data type?
>It is the equivalent of a database field that can be NULL.

         Paul: shock, horror! the null value or the absence of any 
value denoted by null is not really in harmony with the relational model.

> > is it the safe style of programming it encourages/
>Yes.  Consider C, where this is typically done with a NULL pointer, or
>Lisp, where you use the empty list, nil.  These are perfectly good
>values in themselves, while Nothing is just Nothing, if you pardon the
>If I haven't seen further, it is by standing in the footprints of giants

More information about the Haskell-Cafe mailing list