Poor-man's version of threading

[Ted Holden]

Grant Reaber notes that an "after idle" function exists in tcl and for
some reason it is documented in the tk listing rather than under tcl where
I might have expected it. The function schedules one procedure to run on
the next cycle through the tcl control loop when nothing else is
happening, but the function can be chained, i.e. used in a recursive
procedure and, since each copy of the procedure is being scheduled, there
doesn't appear to be any danger of blowing any sort of a stack or
anything. This means that for tasks of a suitably small granularity, i.e.
which can be viewed as a sequence of small steps, none of which takes any
appreciable amount of time to run, you have a sort of a poor-man's
threading capability, and it's totally portable.

Ted Holden
med...@digex.com