CPS 343/543 Lecture notes: Introduction to Squeak


Coverage: [QTOL]

Working with squeak

  • demo of environment
  • local image of everything in your own directory

Basic interaction

  • Workspace window
  • Transcript window
  • System browser

Communicating between windows

  • Transcript show: 'hello'
  • Transcript show: cr
  • 2+3 arithmetic expressions really involve objects communicating through messages
  • browsing through existing classes in the System Browser

Other things to know about Squeak

  • saving and loading classes
  • a convenient way to access all of your code, from which you can copy and paste it to a file, from which you can print it
  • to dump your code to an HTML file, click printOut

Fun stuff

  • morph is the root of all graphical objects in Smalltalk
  • destroying the Energizer bunny - bunny destroy

A sample workspace 

    Transcript open.

Transcript show: 'hello'

3 + 4 7

1 to: 5 do: [:i | (Transcript show: 'Hello World') cr]

prompt _ FillInTheBlank request: 'How may I help you, Linus?'

N _ 6

N class.

<class name> selectors

<class name> superclass.
<class name> allSubclasses.

<class name> withAllSubclasses.
<class name> withAllSuperclasses.

N decrement 6

N _ Dictionary new.

N inspect. "reflection"

N at: '4:30' put: 'cps343'

N at: '5:55' put: 'cps445'

N _ 90.

N inspect. 

Object withAllSubclasses do: 

    [:clas | clas selectors do:
	
         [:sel | 
	         (sel asLowercase includesSubString: 'random')
	 
	          ifTrue: [
		            Transcript show: clas name.
		            Transcript show: ' '.
		            Transcript show: sel.
		            Transcript cr]]].

Morph new openInWorld.

References

    [QTOL] G. Korienek, T. Wrensch, D. Dechow. Squeak: A Quick Trip To ObjectLand.. Addison-Wesley, Boston, MA, 2002.
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