ScalarValuedFunction
In DataFlow, functions are objects implementing the
ScalarValuedFunction interface. A number of commonly used functions are available as part of the function library; predefined functions are listed in
Available Functions.
As with operators, functions are intended to be used as a point of extension. Users can develop new functions that can be used in an identical fashion as those provided by the library. Defining a new function is not generally a matter of creating a new implementation of
ScalarValuedFunction, however. See
Writing a Function for information on creating new functions.
There are two contexts in which
ScalarValuedFunction objects can be used:
• Evaluating a function against a record. This is a much less common usage, typically reserved for the implementation of function-based operators or unit testing of function implementations.