try

(try expr* (catch Class e expr*)* (finally expr*)?)

Evaluates the body expressions and answers the last one. try guards a handler-case inside an unwind-protect: the finally body runs on the way out, and the answer survives it. A catch clause takes an exception whose class is the class it names or a subclass of it; the clauses are tried in order, the first that takes the exception runs with its variable bound to it, and an exception no clause takes passes on to the handlers outside, after the finally -- like the oracle. The class resolves dotted, imported or as a java.lang default import, and must be a Throwable; anything else is the oracle's refusal (Unable to resolve classname: Foo).

A runtime error is the Common Lisp condition the runtime signals, and a catch takes it by the class the oracle throws there: a type error is a ClassCastException (a NullPointerException for nil, an IndexOutOfBoundsException for an index past its bound, an UnsupportedOperationException for count of a value that is no collection), an arithmetic error an ArithmeticException, a wrong argument count a clojure.lang.ArityException, a failed open a java.io.FileNotFoundException. A refusal of the runtime is taken by the class the oracle throws for the same call ((first 5) an IllegalArgumentException, a failed assert an AssertionError); an error naming no class by any catch but clojure.lang.ExceptionInfo's (Deviations). On the interpreter and the JVM, an exception a Java member throws is the host's own, as in the oracle: a catch takes it by its class and binds that object. The caught exception is what ex-message/ex-data/ex-cause, .getMessage/.getCause and str read.