Deducing type information from context in Ada based PDLS

The paper describes a new algorithm for deducing type information of partially declared objects in Ada based PDLs (program design languages). The type information is deduced from the usage context of the objects. The algorithm tries to implement an `insight´ into the design, by checking every detail in the design using all available information deduced from its usage. In this way, the algorithm provides better type checking of incomplete designs, which allows earlier detection of design errors. This algorithm is intended to be a part of an Ada based PDL processor. A prototype of this algorithm was implemented in Prolog. Some examples demonstrating the usefulness of the algorithm are given with their resource consumption. The implementation described indicates that this algorithm should be a worthwhile addition to any Ada based PDL processor