comp.lang.ruby

Eric Hodel

6/22/2007 8:13:00 AM

On Jun 21, 2007, at 21:04, Seth wrote:

> From:
> http://www.rubycentral.com/book/tut_excep...
>
> --- BEGIN
> When you need to raise an exception, you can use one of the built-in
> Exception classes, or you can create one of your own. If you create
> your
> own, you might want to make it a subclass of StandardError or one
> of its
> children. If you don't, your exception won't be caught by default.
> --- END
>
> My question is *why* doesn't it handle the most generalized class,
> Exception, by default? What's the logic behind this?

From http://www.zenspider.com/Languages/Ruby/QuickR...:

Exception
NoMemoryError
ScriptError
LoadError
NotImplementedError
SyntaxError
SignalException
Interrupt
StandardError (default for rescue)
[...]
SystemExit
fatal

You don't want to rescue any of these other exceptions (besides
StandardError and friends) unless you really know what you're doing.

Don't create your own exception classes by subclassing Exception
directly, subclass the closest matching exception class, or subclass
RuntimeError or StandardError.

--
Poor workers blame their tools. Good workers build better tools. The
best
workers get their tools to do the work for them. -- Syndicate Wars