Ken Tilton wrote:
Recently some evil programming took forever to debug because I was re-entering a rule without realizing it. After figuring out that that was happening and fixing the cause of that, I looked to see why rule re-entrance had not been detected, which I seemed to recall it always had been.
Turns out the rule began with without-c-dependency as a trick to run only once. That macro simply:
`(let ((cells::*call-stack* nil)) ,@body)
And that worked because the dependent cell was always identifed as (car cells::*call-stack*).
In case that last bit is not clear, what I meant was "That worked [to avoid dependency] because the dependent cell was identified by taking the car of the *call-stack*"
btw, note that this undetected re-entrance would happen if /any/ rule in the chain leading back to the same cell did a without-c-dependency.
kt