[m-dev.] Arithmetic switch construct

Fergus Henderson fjh at cs.mu.OZ.AU
Wed Feb 7 23:58:19 AEDT 2001


On 07-Feb-2001, Fergus Henderson <fjh at cs.mu.OZ.AU> wrote:
> On 07-Feb-2001, Ralph Becket <rbeck at microsoft.com> wrote:
> > Having if-then-else expressions is very handy; however, I've often
> > thought that having switch expressions would also be useful.
> > 
> > That is, rather than writing something like
> > 
> > 	f(X) = Y :-
> > 		( X = cons1, Y = result1
> > 		; X = cons2, Y = result2
> > 		(etc.)
> > 		).
> > 
> > one could write
> > 
> > 	f(X) =
> > 		( X = cons1, result1
> > 		; X = cons2, result2
> > 		(etc.)
> > 		).
> 
> Why not write that as
> 
> 	f(cons1) = result1.
> 	f(cons2) = result1.

Sorry, I mean

 	f(cons1) = result1.
 	f(cons2) = result2.
		 	 ^

of course.

> ?
> 
> Perhaps you have a better motivating example? ;-)

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
                                    |  of excellence is a lethal habit"
WWW: <http://www.cs.mu.oz.au/~fjh>  |     -- the last words of T. S. Garp.
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