Re: continuations in Scheme (was: Google Summer of Code 2011)

[Alex Queiroz <asandroq@...>]

Hallo,

On Tue, Feb 22, 2011 at 11:02 AM, David Kastrup <dak@gnu.org> wrote:
>
> Local _scalar_ variables are "rolled back".  This discrepancy is a
> general trait of Lisp-like languages.  With increasingly cleaner
> language constructs (proper lexical bindings, proper closures, proper
> continuations etc), it becomes more and more apparent that the
> functional character of the language is not reflected into the behavior
> of its data structures.
>

     Nothing is never rolled back. This "rolling back" is not and has
never been part of Scheme semantics. Maybe you should post an example
to show when this "rolling back" takes place. What is a "scalar
variable", anyway? Lists are just chainings of pairs, a fundamental
data type, and are not special in any way.

[skipped nonsense]

>
> But the data implications for rereturning to a previously established
> dynamic state are not used as a serious programming paradigm, like
> stateful backtracking, as a chess program using alpha-beta pruning would
> do.
>

     You mean not really used as a serious programming paradigm like in Schelog?

http://www.ccs.neu.edu/home/dorai/schelog/schelog.html

-- 
-alex
http://www.artisancoder.com/