Method and system for developing data integration applications with reusable functional rules that are managed according to their output variables

A system for defining functional rules for a data integration application such that said functional rules may be reused in the same data integration application or in other data integration applications, the system comprising:

• a. a persistent data store that is operable to store computer-readable data and to store relations among said data;
• b. logic for receiving a functional rule as part of a first data integration application and storing said functional rule in the persistent data store, wherein a functional rule comprises a set of programmatic expressions that operate to consume a set of input values and to produce an output value, and wherein the output value is represented by a first semantic name that indicates the meaning of the output value;
• c. logic for associating the received functional rule with the first semantic name in the persistent data store;
• d. logic for receiving a second semantic name and recalling from the persistent data store a functional rule associated with the second semantic name;
• and
• e. logic for importing the recalled functional rule into a second data integration application;
• f. such that a functional rule received as part of a first data integration application whose output value is represented by a semantic name may be reused in a second data integration application that refers to the same semantic name.