The problem is this:
- Java's Exception class can only carry a String as its payload. That is often inadequate. We would like our exceptions to carry anything we tell them to (i.e. an Object).
- In clojure it is difficult to subclass a concrete class - it requires AOT compilation, or mixing Java code into your clojure project, or other shenanigans.
This project aims to be the absolute simplest possible solution to this problem.
(ns my.ns
(:import (clj_ex BasicException)))
(try
(throw (BasicException. {:anything ["whatever" "you" "want"]
:message "oops, it's borked!"}))
(catch BasicException e
(println e) ;; #<BasicException clj_ex.BasicException: oops, it's borked!>
(println (.data e)) ;; {:anything [whatever you want], :message oops, it's borked!}
))
That's all - just a subclass of Exception that:
- Takes an Object argument to its constructor
- Returns its constructor argument via the
datamethod - Uses the value of
:message(if supplied) as its message (returned from getMessage and used in toString)
Other higher-level utilities, such as throw/catch macros with destructring, are deliberately omitted. This is just meant to be a building block.
Copyright (C) 2011 Chris Perkins
Distributed under the Eclipse Public License, the same as Clojure.