Bertram:
Absence of a value (something that I think a null for a double
is intended to indicate) is a key property of a model of computation.
I'm not sure that representing it in a data type is a good approach.
In particular, a key property of process networks and dataflow is
that absence is not
Hello,
We have a question about the extensibility of the Ptolemy II type
system. In our project, we need to extend the type system by adding new
data types and modifying the type hierarchy. As an example, we need to
incorporate a new double type (as a superclass of double) that accepts
null, or
