[plt-scheme] Fun with Unicode and delimited continuations

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Thu Jun 3 09:08:02 EDT 2010

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. 

;; --- 

Of course, one can also shift (pardon the pun) reset around
and start discussions of backtracking computations at this 
point and more stuff like that. 

>> 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. 

-- Matthias

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