Keith Wansbrough wondered:
| Does anyone have an example of a useful data type
| involving negative recursion?
Here is an example straight from practice. If we want to
implement a datatype of predicate logic formulas, it is
convenient to use higher-order syntax:
type Name
= String
da
Lars Henrik Mathiesen wrote:
>
> > From: Keith Wansbrough <[EMAIL PROTECTED]>
> >
> > Hi... I'm currently looking at the semantics of recursive data types.
> > One thing that Haskell allows, but the semantics for it is very hairy,
> > is *negatively
> From: Keith Wansbrough <[EMAIL PROTECTED]>
> Date: Wed, 04 Jul 2001 18:27:05 +0100
>
> Hi... I'm currently looking at the semantics of recursive data types.
> One thing that Haskell allows, but the semantics for it is very hairy,
> is *negatively* recursive dat
Hi... I'm currently looking at the semantics of recursive data types.
One thing that Haskell allows, but the semantics for it is very hairy,
is *negatively* recursive data types. That is, data types where the
recursion occurs to the left of a function arrow. For example:
data Ne
