Error Analysis and Reporting in Programming Environments

A programming environment combines elementary operations into single composite operations to be applied by the user. The operands of the composite operation may be decomposed, their components processed by elementary operations, the results combined in arbitrary ways and manipulated by other elementary operations, and a final product delivered to the user. If one of the elementary operations detects an inconsistency in its data, the raw report of that inconsistency will almost certainly be incomprehensible to the user. The programming environment must therefore be capable of using information about its own structure to process the raw report and provide the user with relevant diagnostics. We have developed a general approach to the design of such error recovery mechanisms and demonstrated its usefulness in an experimental programming environment. Our technique can also be used to provide a comprehensive help facility based on a hypertext version of the system documentation.