[Newbies] Where is the setter for self?

Chris Cunnington smalltalktelevision at gmail.com
Fri Jun 1 17:18:53 UTC 2012


Yea, I'm not asking this very well. And all things Renggli make my head 

In image2, if I inspect the string 'bob' I see self contains a string 
called 'bob'. It does not say "a ByteString", which to me means the 
usual behaviour has been overtaken by something else. We don't get an 
instance; we get only its return value. The instance "a ByteString" was 
no longer as important as its return value.

In image1, Lukas has overwritten Object>>printString: in 
SUObject>>printString:. And he's using a pattern ("composite with 
decorations" or something) to represent the domain of the JavaScript 
language in Smalltalk.

If I print "SUSlider new" I don't get "a SUSlider". I get a string of 
JavaScript. What is printed out is what is found in self. If I inspect 
"SUSlider new" I can see in self the string that will be produced. I can 
also see in the decoration instance variable "a SUCreate". With each 
decoration in the chain he makes the string in self gets longer. If I 
execute that entire piece of code from "SUSlider new" down to 
"onChange:" I will get a string of pure JavaScript.

If how I'm asking this is still really confusing, I'll have to sit on it 
for a few days. I seem to do my best comprehending when I'm asleep.


On 12-06-01 12:45 PM, Bert Freudenberg wrote:
> On 01.06.2012, at 17:42, Chris Cunnington wrote:
> It's a bit hard to make out what you are actually asking.
> If you implement "printOn:" in any class, then this method determines how instances are printed.
> "self" always refers to the receiver object of the currently executing message. It cannot be stored into.
> (LimitedWriteStream on: aString) creates a new stream writing to a string. It inherits "on:" from PositionableStream, which puts aString into the stream's "collection" variable.
> The "printOn:" method of an object gets a stream passed as its argument. It then sends messages like "nextPut: something" to the stream, which appends something to its collection.
> What else would you like to know?
> - Bert -
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