Type propagation for automatic casting of output types in a data flow program

A method for implicit downcasting in a data flow program, comprising:

• identifying a first data flow function in an object-oriented data flow program that comprises at least one input of a parent data type and at least one output of the parent data type;
• analyzing the first data flow function to determine if the at least one output preserves the run-time data type of the at least one input;
• identifying a second data flow function in the object-oriented data flow program that comprises a program element that calls the first data flow function, passing an input parameter of a child data type of the parent data type as input;
• if said analyzing determines that an output parameter returned by the at least one output of the first function will always be of the child data type,
• automatically configuring the program element to downcast the output parameter from the parent data type to the child data type at run-time.

A system for implicit downcasting in a data flow program:

• a processor;
• and
• a memory medium coupled to the processor, wherein the memory medium stores program instructions which are executable by the processor to:
• identify a first data flow function in an object-oriented data flow program that comprises at least one input of a parent data type and at least one output of the parent data type;
• analyze the first data flow function to determine if the at least one output preserves the run-time data type of the at least one input;
• identify a second data flow function in the object-oriented data flow program 4 comprises a program element that calls the first data flow function, passing an input parameter of a child data type of the parent data type as input;
• if said analysis determines that an output parameter returned by the at least one output of the first function will always be of the child data type,
• automatically configure the program element to downcast the output parameter from the parent data type to the child data type at run-time.