On 04/14/2011 05:08 AM, Toon Verwaest wrote:
Right, so you confirm the experience of Dale.
In the case of flagging errors without classes, do you generally just use a simple symbol, or concatenate strings to convey more details? This last seems somehow a bad idea... but maybe if it's never caught it's not so relevant?
Using Sven's hierachy as a starting point and taking some cues from the GemStone exception hierarchy, I would suggest the following (names atarting with # are reasonCodes in the namespace of the parent exception class, instead of a unique class): Exception (messageText reasonCode) Abort Error NumericError #floatingPointException #rangeError #naNError ZeroDivide (dividend) FileStreamException (fileName) #fileDoesNotExistException #fileExistsException (fileClass) #cannotDeleteFileException #fileWriteError #fileReadError ** #fileClosedException ** #cannotAccessFileException ** #readonlyFileException ** MessageNotUnderstood (message, receiver) #nonBooleanReceiver (object) OutOfMemory < handlers?> ControlInterrupt Halt AssertionFailure BreakPoint CompileError SyntaxError ** !exists! (input, position) #numberFormatException ** #headlessError ** TimedOut ** (object, operation, timeout) VerificationException IllegalOperation ** (operation, object) #sizeMismatch (objects) #subclassResponsibility ** (message, receiver) #notYetImplemented ** (message, receiver) #cannotInstanciate ** (class) #readOnlyObject ** (object) OutOfFreeSpace ** <handlers?> #invalidArgument ** (message, receiver, argument) #notIndexable ** (object) #noKeyedAccess ** (object) #nonIntegerIndex ** (receiver, index) #subscriptOutOfBounds ** (receiver, index, from, to) NotFoundException ** (receiver, object) #keyNotFound ** #valueNotFound ** #elementNotFound ** StreamException (stream) #positionError ** (index, from, to) EndOfStream ** #beginOfStream ** Notification Admonition LowMemory ** <this should be a notification not an error>