Signaling an exception
Exceptions are signaled by sending one of the following methods to the appropriate instance of ExceptionalEvent: 
signal 
Invokes the exception with no arguments. 
signalWith: 
Invokes the exception with a single argument. 
signalWith:with: 
Invokes the exception with two arguments. 
signalWithArguments: 
Invokes the exception with anArray of arguments 
The following examples signal a couple of types of exception: 
Example: signaling end of file
| anEndOfFileException |
(anEndOfFileException := ExAll newChild)
    description: 'end of file'.
anEndOfFileException signal.
Example: signaling message not understood
| aMessageNotUnderstoodException |
(aMessageNotUnderstoodException := ExAll newChild)
    description: 'message not understood'.
aMessageNotUnderstoodException
    signalWith: (DirectedMessage selector: #halt arguments: #() receiver: self)
When an exception is signaled, an instance of class Signal is created that contains information describing the circumstances where the exception occurred. 
Last modified date: 01/29/2015