IBM Streams 4.2.1

Operator parameters

Different invocations of the same operator can yield different expansions, by providing actual parameter values for formal parameter placeholders declared in the operator definition.

Operators as parameters to composite operators
A composite operator encapsulates a subgraph and some of the operators in that subgraph can be given to the composite operator as parameters at the time of invocation.
Other operator parameters
Both composite and primitive operators can be customized by parameters such as the name of an attribute in an input port, or an expression to be used to filter data.
Operator parameter passing semantics
Operator parameters in SPL behave similarly to macro expansion, but the semantics are designed to prevent macro mistakes common in languages like C.
Operator parameter modes
A parameter declaration in a composite operator definition must specify an expression mode, and can optionally specify a default value.

Parent topic: Operator definitions