prasadtalasila · May 21, 2017 16:09
diff --git a/Dan Ingalls notes b/Dan Ingalls notes

 Smalltalk has
    Class - defines behaviors of instances
    Object - an instance of some class
    Selector - Name of a message
    Message - selector with parameters
    Method - code / procedure found in class for responding to a message


 It is not essential to have classes, we can do OOP with just objects


 Static types are not a requirement for OOP. Smalltalk usually follows dynamic types, but one version of smalltalk did have static types. That turned out to be not so useful.

 Inheritance is not a requirement for polymorphism.

 Smalltalk code initially ran 50 to 100 times slower than procedural code. Now it runs 5 to 10 times slower. (circa 1991)
 Smalltalk mostly gets slowed down by the persistence requirement

 OO code runs much slower than machine code.

	Smalltalk has
	Class - defines behaviors of instances
	Object - an instance of some class
	Selector - Name of a message
	Message - selector with parameters
	Method - code / procedure found in class for responding to a message


	It is not essential to have classes, we can do OOP with just objects


	Static types are not a requirement for OOP. Smalltalk usually follows dynamic types, but one version of smalltalk did have static types. That turned out to be not so useful.

	Inheritance is not a requirement for polymorphism.

	Smalltalk code initially ran 50 to 100 times slower than procedural code. Now it runs 5 to 10 times slower. (circa 1991)
	Smalltalk mostly gets slowed down by the persistence requirement

	OO code runs much slower than machine code.