An aspect of this invention is a method that includes receiving input data from an application. The input data includes information descriptive of at least one field. The method further includes processing the input data to form an array composed of legal data for the at least one field. The array is formed by merging a result of processing syntactic constraints and a result of processing semantic constraints. The method further includes outputting the array to the application. A system for performing the method is also described, as is a computer program product that can be used to execute the method.