The Persistent Abstract Machine

Abstract

The Persistent Abstract Machine is an integral part of a layered architecture model to support the Napier language. It interfaces cleanly with a persistent store, and allows persistence to be implemented without difficulty in a high-level language. The heap based storage mechanism of the Persistent Abstract Machine is designed to support the block retention nature of the Napier language. This allows the implementation of first class procedures and modules in programming languages with the minimum of effort. A primitive type system within the machine contains just enough information to allow machine instructions which behave differently according to the dynamic type of their operands. This type system, in conjunction with the block retention architecture, may be used to great effect to provide a fast implementation of polymorphic procedures, abstract data types, inheritance and bounded universal quantification.