Little Smalltalk Version 4 Distribution
Little Smalltalk, version 4.0
Timothy A. Budd, budd@cs.orst.edu
Oregon State University
Important Note!
Many changes have occured to this code since Dr. Budd originally wrote
both this ReadMe file and LST 4.0. See the file
ReadMe2.html for the changes. We now continue with
our regularly scheduled ReadMe...
I first started developing Little Smalltalk back in 1984, and to tell the
truth hadn't touched it for several years now. However, when I attended
OOPSLA in Portland a few months ago, several things struck me
- Addison-Wesley was still selling my book ``A Little Smalltalk''
(despite it being many years old now and very very dated), and people were
still buying it (don't ask my why).
- There was a heck of a lot of interest in Smalltalk on the vendor floor.
- People kept asking me about Little Smalltalk.
These things combined to make me think perhaps I should
revisit Little Smalltalk. It my spare time since then I've been
updating the system, and this is the result.
What Little Smalltalk is, and more importantly, what it isn't
First and foremost, let me say at the beginning in as LOUD
a voice as I can that Little Smalltalk is NOT a
smalltalk-80 system. If you want a real
Smalltalk system go buy one from ParcPlace, Digitalk, IBM, or whomever.
Little Smalltalk is a sort of fun experiment in building a minimal
smalltalk system. The source code for the interpreter is less than 1800
lines of code. The image consists of less than 4000 objects. It runs
in almost no memory. In short, it's small, it's reasonably fast, it's easy
to understand, and easy to modify.
As you might expect, in order to get Smalltalk to run in something this
small, I've had to make lots of changes. Here are the most notable:
- No graphics.
- The user interface is a more conventional real-eval-print loop (like
most Lisp systems), not a browser. (But it is all written in
Smalltalk itself, so you can modify it if you wish).
- Primitives and cascades are handled as they were in earlier Little
Smalltalk systems, which is not how they are handed in Smalltalk-80.
- The standard class hierarchy differs considerably from Smalltalk-80.
- My basic collections are List, Tree,
Dictionary, Array and String
- The only numbers in the standard image are large and small integers
(adding fractions and floats might be an interesting exercise, however).
Obtaining the system
Anyway, if after this you still want to play with the system,
here are the details. You can ftp from
ftp.cs.orst.edu.
The file
you are reading is found in
/users/b/budd/little
on that system, and the
file names I'm going to mention in a moment are found in that directory.
Or, if you are using a www browser, you can set the option to copy
sources to disk, and read the following files.
- distr.tar
contains the entire distribution as a tar file. Alternatively, you can
get it piece by piece.
- The interpreter is contained in three files:
main.c
(the main driver),
interp.c
(the bytecode interpreter),
memory.c
(the garbage collection system).
- The standard image is found in the binary file named
LittleSmalltalkImage
- Various test cases are found in a shar file named
Tests.
To run the test cases use the fileIn: command (see ``documentation'' below).
I've only compiled the system on a sys-v based Unix system -- but it uses
nothing out of the ordinary so it may work on other systems. Let me know
what problems you run into.
Documentation
Documentation is, as usual, rather spare. In my spare time when I'm not
hacking the system I am revising the Little Smalltalk book, and a few
sample chapters are available in postscript form in
book.ps.
Last words
Have fun. Maybe this will be a real system some day.
But I didn't think I should hold up distribution until that point.
Redistribution Rights and Standard Disclaimer
Little Smalltalk can be freely and widely redistributed if not for
profit and as long as the markings indicating origination are retained.
The system is not supported (it's only a hobby for me), and is, of course,
not warrentied as suitable for any use whatsoever.