Interfacing to the Programmer's Apprentice

This paper has been submitted to SoftFair, an IEEE/NBS/SIGSOFT co-sponsored conference on software development tools, techniques, and alternatives, which will be held at the Hyatt Regency Crystal City, Arlington, VA., July 26-28, 1983.In this paper, we discuss the design of a user interface to the Knowledge Based Editor (KBE), a prototype implementation of the Programmer's Apprentice. Although internally quite sophisticated, the KBE hides most of its internal mechanisms from the user, presenting a simplified model of its behavior which is flexible and easy to use. Examples are presented to illustrate the decisions which have led from high-level design principles such as "integration with existing tools" and "simplicity of user model" to a working implementation which is true to those principles.MIT Artificial Intelligence Laborator

Code Generation in the Programmer's Apprentice

The Programmer's Apprentice is a highly interactive program development tool. The user interface to the system relies on program text which is generated from an internal plan representation. The programs generated need to be easy for a programmer to read and understand. This paper describes a design for a code generation module which can be tailored to produce code which reflects the stylistic preferences of individual programmers.MIT Artificial Intelligence Laborator

Plan Recognition in a Programmer's Apprentice

This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the Laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense under the Office of Naval Research contract N00014-75-C-0643.Brief Statement of the Problem: Stated most generally, the proposed research is concerned with understanding and representing the teleological structure of engineered devices. More specifically, I propose to study the teleological structure of computer programs written in LISP which perform a wide range of non-numerical computations. The major theoretical goal of the research is to further develop a formal representation for teleological structure, called plans, which will facilitate both the abstract description of particular programs, and the compilation of a library of programming expertise in the domain of non-numerical computation. Adequacy of the theory will be demonstrated by implementing a system (to eventually become part of a LISP Programmer's Apprentice) which will be able to recognize various plans in LISP programs written by human programmers and thereby generate cogent explanations of how the programs work, including the detection of some programming errors.MIT Artificial Intelligence Laboratory Department of Defense Advanced Research Projects Agenc

Interactive specification acquisition via scenarios: A proposal

Some reactive systems are most naturally specified by giving large collections of behavior scenarios. These collections not only specify the behavior of the system, but also provide good test suites for validating the implemented system. Due to the complexity of the systems and the number of scenarios, however, it appears that automated assistance is necessary to make this software development process workable. Interactive Specification Acquisition Tool (ISAT) is a proposed interactive system for supporting the acquisition and maintenance of a formal system specification from scenarios, as well as automatic synthesis of control code and automated test generation. This paper discusses the background, motivation, proposed functions, and implementation status of ISAT

On acquisition of programming knowledge

For the evolving discipline of programming, acquisition of programming knowledge is a difficult issue. Common knowledge results from the acceptance of proven techniques based on results of formal inquiries into the nature of the programming process. This is a rather slow process. In addition, the vast body of common knowledge needs to be explicated to a low enough level of details for it to be represented in the machine processable form. It is felt that this is an impediment to the progress of automatic programming. The importance of formal approaches cannot be overstated since their contributions lead to quantum leaps in the state of the art

Plan Verification in a Programmer's Apprentice

This report describes research done at the Artificial Intelligence Laboratory of the Massachusetts Institute of Technology. Support for the Laboratory's artificial intelligence research is provided in part by the Advanced Research Projects Agency of the Department of Defense under the Office of Naval Research contract N00014-75-C-0643.Brief Statement of the Problem: An interactive programming environment called the Programmer's Apprentice is described. Intended for use by the expert programmer in the process of program design and maintenance, the apprentice will be capable of understanding, explaining and reasoning about the behavior of real-world LISP programs with side effects on complex data-structures. We view programs as engineered devices whose analysis must be carried out at many level of abstraction. This leads to a set of logical dependencies between modules which explains how and why modules interact to achieve an overall intention. Such a network of dependencies is a teleological structure which we call a plan; the process of elucidating such a plan stucture and showing that it is coherent and that it achieves its overall intended behavior we call plan verification. This approach to program verification is sharply contrasted with the traditional Floyd-Hoare systems which overly restrict themselves to surface features of the programming language. More similar in philosophy is the evolving methodology of languages like CLU or ALPHARD which stress conceptual layering.MIT Artificial Intelligence Laboratory Department of Defense Advanced Research Projects Agenc

Formalizing the Expertise of the Assembly Language Programmer

A novel compiler strategy for generating high quality code is described. The quality of the code results from reimplementing the program in the target language using knowledge of the program's behavior. The research is a first step towards formalizing the expertise of the assembly language programmer. The ultimate goal is to formalize code generation and implementation techniques in the same way that parsing and code generation techniques have been formalized. An experimental code generator based on the reimplementation strategy will be constructed. The code generator will provide a framework for analyzing the costs, applicability, and effectiveness of various implementation techniques. Several common code generation problems will be studied. Code written by experienced programmers and code generated by a conventional optimizing compiler will provide standards of comparison.MIT Artificial Intelligence Laborator

Program Understanding through Cliché Recognition

We propose research into automatic program understanding via recognition of common data structures and algorithms (clichés). Our goals are two-fold: first, to develop a theory of program structure which makes such recognition tractable; and second, to produce a program (named Inspector) which, given a Lisp program and a library of clichés, will construct a hierarchical decomposition of the program in terms of the clichés it uses. Our approach involves assuming constraints on the possible decompositions of programs according to the teleological relations between their parts. Programs are analyzed by translating them into a language-independent form and then parsing this representation in accordance with a context-free web grammar induced by the library of clichés. Decompositions produced by this analysis will in general be partial, since most programs will not be made up entirely of clichés. This work is motivated by the belief that identification of clichés used in program, together with knowledge of their properties, provides a sufficient basis for understanding large parts of that program's behavior. Inspector will become one component of a system of programs known as a programmer's apprentice, in which Inspector's output will be used to assist a programmer with program synthesis, debugging, and maintenance.MIT Artificial Intelligence Laborator

Understanding LISP Programs: Towards a Programmer's Apprentice

Work reported herein was conducted at the Artificial Intelligence Laboratory, a Massachusetts Institute of Technology research program supported in part by the Advanced Research Projects Agency of the Department of Defense and monitored by the Office of Naval Research under Contract Number N00014-70-A-0362-0005.Several attempts have been made to produce tools which will help the programmer of complex computer systems. A new approach is proposed which integrates the programmer's intentions, the program code, and the comments, by relating them to a knowledge base of programming techniques. Our research will extend the work of Sussman, Goldstein, and Hewitt on program description and annotation. A prototype system will be implemented which answers questions and detects bug in simple LISP programs.MIT Artificial Intelligence Laborator