Really Useful CD 1/ReallyUsefulCD1.iso/extras/languages/smalltalk/read_me

Text File | 1990-05-23 | 4.0 KB | 102 lines

Little Smalltalk - notes on this version.

This version was written by:

        Mark Allerton,
        Flash Monkey Software,
        38 Chandos Way,
        Golders Green,
        London NW11 7HF

        Tel: [phone]
        Fax: [phone]
        E-Mail: [e-mail]
                akapascal on Cryton BBS.

This version of Little Smalltalk is based on the version
supplied by Smalltalk Express. The original Read_Me file
supplied with that version is kept here as Read_Me_2.

So, what's different about this version?

Mainly, it has been made into a proper Risc OS application,
which means:

a) the source has been fixed to work with Acorn C version
3, and a lot of things which where very kludgy in the
previous version (mainly due to Arthur being useless) make
use of Risc OS features.

b) It is a proper desktop application. It has an icon on
the iconbar, and a workspace window. I've modelled the
workspace window as closely as possible on the ones I've
seen in Smalltalk/V and Actor.

c) It doesn't rely on being in the root directory anymore.
You can put the !SmallTalk application wherever you like,
but, unless you remove the source code, you will need a
hard disk to run it.

The orginal version could be persuaded to run on a 1MByte
machine, but Risc OS being what it is, I doubt this one
will, though I haven't tried it. Sorry.

This is by no means a finished product: it was just
something I knocked up over a couple of days. Some features
are missing, for instance the ability to save the contents
of the workspace, which would be nice. I may fix these in
future: however, feel free to take the source and run with
it if there's something you'd like to add. The conditions
attached to the use of the source are detailed in the
Read_Me_2 file.


Using this version.

This is not intended as a proper manual for Little
Smalltalk: as always you are recommended to read the book
"A Little Smalltalk" by Timothy Budd,  published by Addison
Wesley (ISBN 0-201-10698-1.)

When you launch the !Smalltalk app from the desktop there
will be a short wait while it loads itself and all of the
base classes from disk. This done, it will put the
SmallTalk icon on the icon bar. This icon has three
functions: the usual "Info" and "Quit" options, available
from the menu, and loading in class definitions. Loading a
class defintion is acheived by dropping a (text) file with
the class definition in it onto the SmallTalk icon. This
supercedes the )i command within Little Smalltalk. Class
definitions can be edited using !Edit and dropped onto the
icon, so the )e command is pretty superfluous too.

Little Smalltalk also opens a "Workspace Window", which is
where you do most of the work of using the program. The
workspace is a text editor window: you can type more or
less anything you like into it, and edit it using the
normal mouse clicks and cursor keys (as used in !Edit, for
instance.) This may not seem to achieve very much, but the
fun starts when you select an area of text by dragging the
mouse over it. For example, try typing "1 + 3 + 4" into the
workspace. Now select it using the mouse, and then click
the Menu button on the mouse: you should see a menu that
has the options "Copy", "Delete" and "Execute". Copy copies
the selected text to the current cursor position, Delete
deletes the selected text, and Execute executes the text as
a piece of Smalltalk code. Try "Execute" and you should see
"8" appear at the cursor position: this is the result of
the SmallTalk operations "1 + 3 + 4". The result of any set
of Smalltalk operations selected and executed will always
appear at the cursor position in the workspace. The area
selected remains selected after the code has been executed,
so the operation can be repeated, or the code can be
modified and re-executed.

Note that while a piece of Smalltalk code is being
execueted, multitasking is suspended. This would be
slightly fiddly to code around, to say the least.

Anyway, enjoy!