A simple Clojure library that allows one to dynamically define Java Exception classes in Clojure.
Sometimes you just want a quick Exception class that you can catch
directly. defexception uses clojure.asm to dynamically create a
Java class that directly inherits from clojure.lang.ExceptionInfo.
The created exception class does not add any behavior to clojure.lang.ExceptonInfo.
To create your own exception class you can do this:
(ns foo.bar
(:require '[com.rpl.defexception :refer [defexception]]))
(defexception MyException)This will create the foo.bar.MyException class that inherits from
clojure.lang.ExceptionInfo. This will also import the class into
the current namespace and create a helper function
foo.bar/->MyException to help you construct the exception class.
Now you can do this:
(try
(throw (->MyException "My bad!" {:my-bad 1}))
(catch MyException e
(ex-data e)))
;; => {:my-bad 1}The generated ->MyException helper function has several signatures
to help you instantiate your exception.
;; creates an exception with no message or ex-data
(->MyException)
;; creates an exception with only ex-data
(->MyException {:hello 1})
;; creates an exception with only a message
(->MyException "My Bad!")
;; creates an exception with both a message and ex-data
(->MyException "My Bad!" {:hello 1})
;; creates an exception with a message, ex-data and a cause
(->MyException "My Bad!" {:hello 1} (Exception. "The cause"))Care was taken to make these exceptions compatible with Clojure's AOT compilation.
Copyright © 2019 Red Planet Labs Inc.
Distributed under the Eclipse Public License version 1.0