[Newbies] Creating a Form Editor

[Bruce Prior]

Hi Squeakers,

I have been reading Adele Goldberg's classic text, "Smalltalk-80 The 
Interactive Programming Environment," and came across this in Chapter 7, 
"How to make Pictures."

Adele states, "Create a Form Editor by evaluating an expression of the form,

(Form new extent: 300 @ 400) edit"

It didn't work for me in Squeak 3.8 (on my Macintosh).

Further down, Adele says, "The message edit can be sent to any instance 
of Form." But when I checked with my browser I found that Form has a 
class method extent: but not an instance method extent:.

So I tried (Form extent: 300 @ 400) edit and the Form Editor appeared as 
desired. Is this because Smalltalk and Squeak are different somehow, or 
is there a mistake in the text, or?

If the text is correct, then I still don't fully appreciate the 
difference between class and instance methods.

Bruce Prior 
(still looking for "ah - ha!" and I think it's close....)