Benjamin Franksen writes:
On Monday 01 November 2004 23:40, Jon Fairbairn wrote:
Apart from matching up with the names there's not much to choose between one destructor and many, except possibly when one considers something like:
case e of Square s -> ... _ -> ...
particularly if the type has more than two constructors.
True. Anyway, we don't really want to abandon pattern matching syntax, do we?
Explicit destructor functions are nice when working in a point-free
fashion. Consider these:
c1 = someComputation >>= maybe mzero return
c2 = do
x <- someComputation
case x of
Just x' -> return x'
Nothing -> mzero
On the other hand, this function (which I actually have in my code) may
be over-doing it:
swap = maybe (Right Nothing) (either Left (Right . Just))
--
David Menendez