[plt-scheme] Fun with Unicode and delimited continuations

On Jun  3, Matthias Felleisen wrote:
> On Jun 3, 2010, at 8:55 AM, Eli Barzilay wrote:
> 
> > On Jun  3, Matthias Felleisen wrote:
> >> This must be the most fun (and useless) use of delimited
> >> continuations I have seen since 1984.
> > 
> > I'll bite: why is it useless?
> 
> 
> The reset and shift in this case statically determine 
> the delimited continuation: 
> 
>  \x. (/ x (* 2 a))
> 
> if it were prompt/control. 

Looks like I had a better reason to bite than I knew -- how about an
example?

(Speaking about examples, is this too much as a 7-line example of
black magic?)



> >> Eli, I wonder how NUPRL deals with the quadratic formula? Or what
> >> is the logical content of the below?
> > 
> > Real numbers are not that interesting in that world...  (But as
> > for the logical content -- I don't remember much, I didn't go too
> > much beyond being impressed with how call/cc translates.)
> 
> Ignoring the real numbers, I think Tim had an example that used two
> callccs and could have benefited from prompts.

(Ah, I *think* that I've seen some backtracking example, I might have
even did a limited version for fun; but that's well beyond my memory
at this point in the "day".)

-- 
          ((lambda (x) (x x)) (lambda (x) (x x)))          Eli Barzilay:
                    http://barzilay.org/                   Maze is Life!