Browse Prior Art Database

Portable LISP System

IP.com Disclosure Number: IPCOM000034613D
Original Publication Date: 1989-Mar-01
Included in the Prior Art Database: 2005-Jan-27
Document File: 3 page(s) / 16K

Publishing Venue

IBM

Related People

Curtis, DE: AUTHOR [+3]

Abstract

This paper describes two extensions which are possible within the architecture of the Patient Care System-Application Development System (PCS-ADS). The first is the notion of portability within or without a network environment. The second is an overview of a LISP interpreter executing in the PCS-ADS architecture. PCS-ADS has an architecture suited for portable applications. Regardless which CPU or operating system provides "run under" services, a PCS-ADS execution module may be programmed to accept and correctly execute any of the following PCS-ADS application objects: Screens, Print Formats, Data Collection Lists and function commands. Furthermore, PCS-ADS Screens, Print Formats, and Data Collection Lists are records which may be either stored globally in the host or locally in a minicomputer or PC.

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Portable LISP System

This paper describes two extensions which are possible within the architecture of the Patient Care System-Application Development System (PCS-ADS). The first is the notion of portability within or without a network environment. The second is an overview of a LISP interpreter executing in the PCS-ADS architecture. PCS-ADS has an architecture suited for portable applications. Regardless which CPU or operating system provides "run under" services, a PCS-ADS execution module may be programmed to accept and correctly execute any of the following PCS-ADS application objects: Screens, Print Formats, Data Collection Lists and function commands. Furthermore, PCS-ADS Screens, Print Formats, and Data Collection Lists are records which may be either stored globally in the host or locally in a minicomputer or PC. Copies of these application components may be transferred from one location to another on demand. The architecture of PCS-ADS assures functional separability of the individual application components. In other words, there is no functional linkage, such as parameter passing or subroutine addresses. A functionally separable application program is one in which each function, such as the display of a screen, is independent of all other functions in the application. PCS-ADS uses well-known data structures in unique ways to implement this: 1. An independent facility for communicating data between the application functions called the symbol table.

PCS-ADS execution components interface data in the

symbol table with something else. The Screen Manager

interfaces the symbol table with a terminal display,

the Data Manager interfaces the symbol table with

fields in a file record, and other commands manipulate

symbol values. The important point is that anything in

the symbol table is there for all functional components

to examine and use. All data is both global and

modular. 2. An independent facility for controlling the sequence in which functions are executed called the Command Stack.

PCS-ADS applications may control logic flow directly by

passing command requests to the Command Handler or

indirectly by placing them on the Command Stack.

Stacked commands are executed after

the commands stacked on top of them are executed. The

advantage of stacking is that additional logic may be

inserted at any time, and for any reason. A LISP interpreter integrated with PCS-ADS allows porting LISP applications from one hardware architecture to another, function by function, the same as other PCS-ADS objects. Ported functions need not be compiled or linked for the processor on which they will be executed. A LISP interpreter integrated with PCS-ADS also overcomes the problems of interfacing artificial intelligence functions developed in LISP with conventional application dialogs and functions developed with PCS-ADS. LISP has two fundamental structures. They reference both

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data and code. Data and code are intrinsically interchang...