Convivial error recovery
Denis Samson, Yves Ouellet · 1981
This paper presents a new approach to an Event Control Mechanism (ECM) for APL. After an informal review of some typical ECM implementations, it describes the general architecture of an ECM and shows how the mentioned implementations map onto it. An extended ECM is then presented that combines many features of existing implementations with some new capabilities. It gives the user access to the immediate context of the subexpression where an error occurred and introduces new control functions to allow execution to move to a determined calling environment. The proposed additions aim at a “convivial” utilization of the ECM suitable both to automatic control and to interactive debugging of APL applications.