@error{} peculiar error: "My unknown error condition"
@end group
@end smallexample
@end example
@end defun
@cindex CL note---no continuable errors
...
...
@@ -990,7 +988,7 @@ to allow the debugger to run before the handler); @var{body} is one or more
Lisp expressions to be executed when this handler handles an error.
Here are examples of handlers:
@smallexample
@example
@group
(error nil)
...
...
@@ -1000,7 +998,7 @@ Here are examples of handlers:
(message
"Either division by zero or failure to open a file"))
@end group
@end smallexample
@end example
Each error that occurs has an @dfn{error symbol} that describes what
kind of error it is. The @code{error-conditions} property of this
...
...
@@ -1033,9 +1031,9 @@ Sometimes it is necessary to re-throw a signal caught by
@code{condition-case}, for some outer-level handler to catch. Here's
how to do that:
@smallexample
@example
(signal (car err) (cdr err))
@end smallexample
@end example
@noindent
where @code{err} is the error description variable, the first argument
...
...
@@ -1054,7 +1052,7 @@ Here is an example of using @code{condition-case} to handle the error
that results from dividing by zero. The handler displays the error
message (but without a beep), then returns a very large number.
@smallexample
@example
@group
(defun safe-divide (dividend divisor)
(condition-case err
...
...
@@ -1075,22 +1073,24 @@ message (but without a beep), then returns a very large number.
@print{} Arithmetic error: (arith-error)
@result{} 1000000
@end group
@end smallexample
@end example
@noindent
The handler specifies condition name @code{arith-error} so that it will handle only division-by-zero errors. Other kinds of errors will not be handled, at least not by this @code{condition-case}. Thus,
The handler specifies condition name @code{arith-error} so that it
will handle only division-by-zero errors. Other kinds of errors will
not be handled (by this @code{condition-case}). Thus:
@smallexample
@example
@group
(safe-divide nil 3)
@error{} Wrong type argument: number-or-marker-p, nil
@end group
@end smallexample
@end example
Here is a @code{condition-case} that catches all kinds of errors,
including those signaled with @code{error}:
including those from @code{error}:
@smallexample
@example
@group
(setq baz 34)
@result{} 34
...
...
@@ -1108,7 +1108,7 @@ including those signaled with @code{error}:
@print{} The error was: (error "Rats! The variable baz was 34, not 35")
@result{} 2
@end group
@end smallexample
@end example
@defmac ignore-errors body@dots{}
This construct executes @var{body}, ignoring any errors that occur
...
...
@@ -1119,12 +1119,12 @@ otherwise, it returns @code{nil}.
Here's the example at the beginning of this subsection rewritten using
@code{ignore-errors}:
@smallexample
@example
@group
(ignore-errors
(delete-file filename))
@end group
@end smallexample
@end example
@end defmac
@defmac with-demoted-errors body@dots{}
...
...
@@ -1279,7 +1279,7 @@ Variables}).
For example, here we make an invisible buffer for temporary use, and
make sure to kill it before finishing:
@smallexample
@example
@group
(let ((buffer (get-buffer-create " *temp*")))
(with-current-buffer buffer
...
...
@@ -1287,7 +1287,7 @@ make sure to kill it before finishing:
@var{body-form}
(kill-buffer buffer))))
@end group
@end smallexample
@end example
@noindent
You might think that we could just as well write @code{(kill-buffer
...
...
@@ -1312,7 +1312,7 @@ is protected with a form that guarantees deletion of the process in the
event of failure. Otherwise, Emacs might fill up with useless
subprocesses.
@smallexample
@example
@group
(let ((win nil))
(unwind-protect
...
...
@@ -1323,7 +1323,7 @@ subprocesses.
(error "Ftp login failed")))
(or win (and process (delete-process process)))))
@end group
@end smallexample
@end example
This example has a small bug: if the user types @kbd{C-g} to
quit, and the quit happens immediately after the function
