[m-dev.] if-then goals

[Fergus Henderson]

On 24-Jul-2003, Julien Fischer <juliensf at students.cs.mu.OZ.AU> wrote:
> 
> The compiler currently has code for handling goals of the form (if A then B)
> or (A -> B).  However the code in the parser for handling these
> is commented out, with the reason being given that because the
> semantics for standard prolog (A -> B ; fail) are different from those
> for Mercury, (A -> B ; true) this is disallowed for the moment?
> 
> Is the "moment" up?

IMHO no; Prolog is still too popular, and given that Mercury syntax is mostly
like Prolog syntax, it would be confusing if "(A -> B)" meant one thing in
Prolog and something quite different in Mercury.

However, I think it would be OK to allow "(if A then B)", if people want that.

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "I have always known that the pursuit
The University of Melbourne         |  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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