ANSI Common Lisp 9 Conditions 9.1 Condition System Concepts 9.1.4 Signaling and Handling Conditions
When a condition is signaled, the most recent
applicable active handler is invoked.
Sometimes a handler will decline by simply returning
without a transfer of control.
In such cases, the next most recent applicable active handler is
If there are no applicable handlers for a condition that
has been signaled, or if all applicable handlers decline, the
condition is unhandled.
The functions cerror and error invoke the
interactive condition handler (the debugger) rather than
return if the condition being signaled, regardless of
its type, is unhandled. In contrast, signal
returns nil if the condition being signaled,
regardless of its type, is unhandled.
The variable *break-on-signals* can be used to cause the
debugger to be entered before the signaling process begins.
The next figure shows defined names relating to
the signaling of conditions.
Defined names relating to signaling conditions.
220.127.116.11.1 Resignaling a Condition