Software fault-tolerance in functional programming

Abstract

Handing exceptions in functional languages has always been a problem, due to the inherent conflict between the control-flow-oriented approach of exception handlers and the functional style evaluation. The author proposes an approach that discards the conventional view of treating exceptions as a means of effecting control transfer. Instead, exceptions are used to change the state of an object: A terminate exception is viewed as shielding the input object. A resume exception designates the input object as curable and requires the immediate application of a handler function. This approach enables the description of the semantics of exception raising functions without associating any implementation restriction and without the loss of referential transparency and commutating of functions.<>