A nonstrict actor that delays tokens by one iteration.
<p>
This actor provides a one-tick delay. On each firing, it produces
on the output port whatever value it read on the input port in the
previous tick of the clock. If the input was absent on the previous
tick of the clock, then the output will be absent. On the first tick,
the output is <i>initialValue</i> if it is given, and absent otherwise.
In contrast to the Pre actor, this actor is non-strict, and hence can
break causality loops. Whereas Pre provides a one-step delay of
non-absent values, this actor simply delays by one clock tick.
Paul Whitaker, Elaine Cheong, and Edward A. Lee
$Id: NonStrictDelay.java 69607 2014-07-30 17:07:26Z cxh $
Ptolemy II 2.0
Yellow (celaine)
Yellow (cxh)
Initial token value. This defaults to no value, which results
in the first output being absent. If a value is given, then
output will be constrained to have at least the type of the value
(as well as at least the type of the input).