Errors

try guards a handler-case inside an unwind-protect. A catch clause takes an exception of the class it names or a subclass, the clauses in order, and the catch variable binds the exception; a runtime error or a refusal of the runtime is taken by the class the oracle throws for it (try). An exception is a condition on every backend: an ex-info, a construction of a throwable class that carries only a message and a cause ((Exception. "m"), (IllegalArgumentException. "m" cause)), or the Common Lisp condition of a runtime error. On the interpreter and the JVM, an exception a Java member throws and a host Throwable thrown are the host's own objects, which a catch binds.