An Approach to Persistent Programming

Abstract

This paper presents the identification of a new programming language concept and reports our initial investigations of its utility. The concept is to identify persistence as an orthogonal property of data, independent of data type and the way in which data is manipulated. This is expressed by the principle that all data objects, independent of their data type, should have the same rights to persistence or transience. We expect to achieve persistent independent programming, so that the same code is applicable to data of any persistence. We have designed a language PS-algol by using these ideas and constructed a number of implementations. The experience gained is reported here, as a step in the task of achieving languages with proper accommodation for persistent programming.

The Napier88 Persistent Programming Language and Environment

“…The implication of orthogonal persistence is that the user need never write code to move or convert data for long or short term storage [53]. There are three design principles that may be used to achieve orthogonal persistence.…”

“…The Napier88 approach is to ensure that type system is mostly statically checkable. However, some dynamic checking on projection out of unions for types any and env, as well as variant selection, allows the dynamic binding required for orthogonal persistence [53] and system evolution [23].…”

An Integrated Graphics Programming Environment

“…In this way PS-algol provides a secure transaction mechanism on its persistent store. Further reading on the PS-algol system can be found in [1] and [4].…”

“…will produce a unit square with its bottom left hand corner positioned at the point [1,1]. This is illustrated in Figure 1.…”

“…The inclusion of graphics facilities in a programming language that supports an integrated persistent environment yields an ideal base for building large and complex graphics systems [1]. The integrated persistent store allows data to be stored and retrieved automatically from user named databases in a type secure manner.…”