[Haskell-cafe] Maybe a, The Rationale

Ketil Malde ketil at malde.org
Sun May 11 05:01:33 EDT 2008


PR Stanley <prstanley at ntlworld.com> writes:

> 	What is the underlying rationale for the Maybe data type? 

It is the equivalent of a database field that can be NULL.

> 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
pun.

-k
-- 
If I haven't seen further, it is by standing in the footprints of giants


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