On 02/09/10 17:10, Stephen Sinclair wrote:
On Thu, Sep 2, 2010 at 3:25 AM, Jan Christiansen
<j...@informatik.uni-kiel.de> wrote:
I prefer
False<= _|_ = True
Sorry to go a bit off topic, but I find it funny that I never really
noticed you could perform less-than or greater-than comparisons on
Bool values. What's the semantic reasoning behind allowing relative
comparisons on booleans? In what context would you use it? It seems
to me a throwback to C's somewhat arbitrary assumption that False=0
and True=1.
Comparison on Bool itself is probably not particularly useful. But it
is often useful if the Bool is part of a larger data structure. For
example, I might want to have Set (String, Bool); without the Ord
instance on Bool I couldn't do this. Similarly, you couldn't derive Ord
on your data types that have Bool in them without the Ord Bool instance.
Thanks,
Neil.
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