Read in tokens and silently discard any tokens that are marked as
nil. Non-nill tokens are transferred to the output.
<p>In the real world, data sources sometimes pass null values
when data sources are sparsely populated. The null values are sometimes
called missing values. The Ptolemy II expression language represents
the missing or null tokens with the string "nil".
<p>This actor should not be used in the SDF domain because
the number of tokens sent to the output depends on the input.
Christopher Brooks
$Id: RemoveNilTokens.java 70398 2014-10-22 23:44:32Z cxh $
Ptolemy II 5.2
Red (cxh)
Red (cxh)