If then else and unevaluated conditionals



On 1/29/07, Stavros Macrakis <macrakis at alum.mit.edu> wrote:

> That's one way of doing it, though I think an unordered case-like
> statement lends itself to easier manipulation -- essentially
> Dijkstra's guarded clauses.

I'm not opposed to an implementation of guarded clauses, so long
as there is also an implementation of unevaluated if--then--else,
and the two have different syntaxes.

The motivation for unevaluated if--then--else is that I want naive stuff like
plot2d(if x > 0 then 1 else 0, ...) and integrate(if x > 0 then 1 else 0, ...)
and (if x > 0 then 1 else 0)^3, etc, to just work.
Two or more notations for the same idea is a mess this respect.

All the best,
Robert