Error Data Values in the Data-Flow Language VAL

Abstract

The data-flow architecture is intended to support large scientific computations, and VAL is an algebraic, procedural language for use on a data-flow computer. VAL is apt for numerical computations but requires an error monitoring feature that can be used to diagnose and correct errors arising during program execution. Traditional monitoring methods (software traps and condition codes} are inappropriate for VAL; instead, VAL includes a set of error data values and an algebra for their manipulation. The error data values and their algebra are described and assessed; the conclusion is that error values provide a clean way for a high-level language to handle numeric (and some other) errors.