Boolean
Boolean inherits from Object and defines no instance variables. It has subclasses False and True.
To save space, most control flow messages are not implemented in class Boolean---instead, True and False implement them directly.
Methods defined in Boolean:
Methods for copying:
- shallowCopy
Copying Boolean values is not allowed.
Methods for error handling:
- mustBeBoolean
Sent by the VM if the receiver to an #ifTrue: or related message is not true or false.
Pocket Smalltalk Documentation