Continuing Operators

  Before addressing the management of multiple phases in an application, this section will first discuss the one `exception' to the phase-switching model: operators that continue from one phase to the next. Such operators require special handling. For example, as was discussed in Section 2.4.2, a user may wish to have a particular broadcast operator available throughout the application:

If the compiler decides to break up the sequential clause into multiple phases, it becomes necessary to take special measures to ensure that the stdin operator is valid through all the phases. It is important to guarantee that any data that was in transit during a phase change remains valid, and that the operator is available for reading and writing in each phase.