Errors, raise and catch signals

• This page collects a few snippets I find useful to pick up this topic
• You make an error object like this:

Error new messageText: 'fooerr' 

• For the Error to generate an 'error signal' you do

Error new messageText: 'fooerr' ; signal

• You can define your own errors subclassing Error and maybe adding a default messageText and tag.
• Example of catching a risen Error signal

[ Error new messageText: 'fooerr' ; signal  ] on: Error do: [ 
	Transcript log: 'foobar'. 
	].