Aucbvax.2310
fa.works
utzoo!duke!decvax!ucbvax!works
Thu Jul 16 09:39:46 1981
Programming by example
>From Halbert@PARC-MAXC Thu Jul 16 09:36:00 1981
 Here is a short description of programming by example.  I
have gotten requests from a LARGE number of WorkS subscribers
requesting it.

              ------------------------------


Since a few people have mentioned programming by example and
the work I've done on it specifically, I will try to give a
brief outline of what it is, and what I've done:

At its simplest, programming by example is just recording a
sequence of commands to a system, so that the sequence can
be played back at a later time, to do the same or a similar
task.  The sequence forms a program.  The user tells the
system, "Remember what I am doing".  The system executes
the user's commands normally, but also remembers them.

The user has created a program by giving an example what he
wants the program to do.  However, the statements in his
program are the same as the normal system commands.  The
user does not have to learn some programming language with
its attendant syntax and semantics; instead he can do his
programming -in the user interface- of the system, which he
already has to know anyway in order to operate the system.

In addition, he has written the program by performing,
concretely, an example of what the program is supposed to
do.  Since he can easily verify whether he did his example
correctly, he can be fairly confident his program will work.
He does not have to understand his program abstractly.

Naturally, straight line programs without parameters are not
very interesting.  Once the user has written a program he
may want to -generalize- it.  He may want to print file Y,
instead of the file X he used in his example.  So the system
has to provide a way for him to to change the constants in
his programs to variables, and specify how these variables
are to be bound (e.g. by prompting the user, by looking for
similar data, etc.)

The user may also want to insert conditional or looping
constructs into his program.  There are various ways, which
I will not go into here, of inserting these constructs into
programs using programming-by-example techniques.

I would emphasize that this kind of programming by example
does not use inductive inference techniques used in AI,
in which the user does several examples, and the system
inductively determines what has changed from example to
example (e.g. 1+2, 5+2, hmm, first operand must be a
variable; or a[1], a[2], a[3], hmm, looks like a loop
stepping through the array).

The seminal work in programming by example was done by Dave
Smith of Xerox in his Stanford Ph.D. Thesis.  Gael Curry
did similar work in which the examples given by the user
could contain abstract as well as concrete data values.
Certain industrial robots can be programmed by example by
guiding them through the task they are to perform.  Here
at Xerox, I have added programming by example to a prototype
of Star.  The system provides program generalization and
an iteration mechanism as well as simple command recording.
I have written up this work and my ideas on programming by
example so far in a Master's project report done for U.C.
Berkeley. I intend to continue and extend this work into a
Ph.D. thesis.

References:

Daniel C. Halbert.  An Example of Programming by Example.
Master's project report, University of California, Berkeley,
and internal report, Xerox Corporation, Office Products
Division, Palo Alto, CA.

David C. Smith.  Pygmalion: A Computer Program to Model and
Stimulate Creative Thought.  Ph.D. thesis, Stanford University,
1975 and Birkhauser Verlag, 1977.

Gael A. Curry.  Programming by Abstract Demonstration.  Ph.D.
thesis, University of Washington, Seattle.  Technical Report
No. 78-03-02.  March, 1978.

Henry Lieberman and Carl Hewitt.  A Session with Tinker:
Interleaving Program Testing with Program Writing.
Conference Record of the 1980 LISP Conference, Stanford
University, August, 1980.  [describes a programming by
example system for Lisp]

Michael A. Bauer.  Programming By Examples.  Artificial
Intelligence 12: 1-12 (May 1979).  [describes inductive
inference techniques].

Copies of my report are available on request.

  Dan Halbert
  Xerox Corporation
  Office Products Division
  3450 Hillview Avenue
  Palo Alto, California

  or

  Halbert@PARC-MAXC (preferred)
    (or csvax.halbert@Berkeley)

--Dan
-----


-----------------------------------------------------------------
gopher://quux.org/ conversion by John Goerzen <[email protected]>
of http://communication.ucsd.edu/A-News/


This Usenet Oldnews Archive
article may be copied and distributed freely, provided:

1. There is no money collected for the text(s) of the articles.

2. The following notice remains appended to each copy:

The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996
Bruce Jones, Henry Spencer, David Wiseman.

You are viewing proxied material from gopher.quux.org. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.