11. A system for generating a parameter value for an executable statement, comprising: a processor and a memory coupled to the processor, the memory configured to store program code executable by the processor; the program code configured, when executed by the processor, to identify, in a plurality of program statements, an input statement, wherein the input statement comprises input information; the program code configured, when executed by the processor, to identify, in the plurality of program statements, an output statement associated with the input statement; wherein: the output statement comprises a reference to a temporary data set, and another of the plurality of program statements also includes a parameter reference to the temporary data set; the program code configured, when executed by the processor, to modify the input information by performing symbolic substitution on at least a portion of the input information to produce modified input information; and the program code configured, when executed by the processor, to output according to the output statement the modified input information to the temporary data set.
14. The system of claim 11 , wherein the input statement and the output statement are associated with each other because each comprises a respective associated identifier.