On 9/14/06, Jose <jmalv04@gmail.com> wrote:
Hi, Giovanni,
I found 2 papers that shed some light on the solution using one-shot continuations. The key is to detect when the continuation is invoked a second time and provide a suitable error
Interaction-Safe State for the Web http://www.cs.brown.edu/~sk/Publications/Papers/Published/mk-int-safe-state-...
The Influence of Browsers on Evaluators<http://www-spi.lip6.fr/%7Equeinnec/PDF/webcont.pdf> http://www-spi.lip6.fr/~queinnec/PDF/webcont.pdf
Hum, a quick read of the papers seems that they deal on how not executing full continuation a second time by making them one shot in some cases (for example in presence of database updates), so they are not really much relevant. In those papers, the detection is done from *inside* the continuation (a full continuation). We cannot do that and need to do it from the outside. This is nothing new. You need to do it even on web applications not built using continuations of any sorts. An innovative idea would be an easy way to have backtracking with one shot continuations. One of the examples in my library implements backtracking with coroutines. I'll see if it can be expanded, but it would require at least a new coroutine for backtracking point. BTW, posix has a nice and simple way for creating full continuations. It is called 'fork' :). Unfortunately it is a little too heavyweight. -- Giovanni P. Deretta