Am 05.04.2012 um 08:42 schrieb Brandon Allbery:
> On Thu, Apr 5, 2012 at 01:53, Sutherland, Julian
> <julian.sutherlan...@imperial.ac.uk> wrote:
> data Tree = Node Left Right | Leaf
>
> Could be converted to a struct in C/C++:
>
> struct Tree {
> struct Tree* left;
> struct Tree* right;
> };
>
> Shouldn't this actually be a tagged union? Not that they exist as such in
> C/C++, but are easy enough to emulate (minus the extra type checking that
> real tagged unions such as even Pascal gives you):
Not necessarily. The above type is equivalent to
type Tree = Maybe (Left, Right)
(modulo strictness, of course) and the C/C++ convention is to represent Nothing
by a NULL pointer.
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