diff options
| -rw-r--r-- | src/clojure/contrib/except.clj | 45 |
1 files changed, 27 insertions, 18 deletions
diff --git a/src/clojure/contrib/except.clj b/src/clojure/contrib/except.clj index df5e9748..8cb98417 100644 --- a/src/clojure/contrib/except.clj +++ b/src/clojure/contrib/except.clj @@ -8,18 +8,18 @@ ;; ;; except.clj ;; -;; Provides functions that make it easy to specify the class and message -;; when throwing an Exception or Error. The optional message is formatted -;; using clojure/format. +;; Provides functions that make it easy to specify the class, cause, and +;; message when throwing an Exception or Error. The optional message is +;; formatted using clojure.core/format. ;; ;; scgilardi (gmail) ;; Created 07 July 2008 (ns #^{:author "Stephen C. Gilardi", - :doc "Provides functions that make it easy to specify the class and message -when throwing an Exception or Error. The optional message is formatted -using clojure/format."} + :doc "Provides functions that make it easy to specify the class, cause, and +message when throwing an Exception or Error. The optional message is +formatted using clojure.core/format."} clojure.contrib.except (:import (clojure.lang Reflector))) @@ -27,13 +27,14 @@ using clojure/format."} (defn throwf "Throws an Exception or Error with an optional message formatted using - clojure/format. All arguments are optional: + clojure.core/format. All arguments are optional: - class? format? format-args* + class? cause? format? format-args* - class defaults to Exception, if present it must name a kind of Throwable - - format is a format string for clojure/format + - cause defaults to nil, if present it must be a Throwable + - format is a format string for clojure.core/format - format-args are objects that correspond to format specifiers in format." [& args] @@ -56,23 +57,31 @@ using clojure/format."} (defn throw-arg "Throws an IllegalArgumentException. All arguments are optional: - format? format-args* + cause? format? format-args* - - format is a format string for clojure/format + - cause defaults to nil, if present it must be a Throwable + - format is a format string for clojure.core/format - format-args are objects that correspond to format specifiers in format." [& args] (throw (throwable (cons IllegalArgumentException args)))) +(defn- throwable? + "Returns true if x is a Throwable" + [x] + (instance? Throwable x)) + (defn- throwable - "Constructs a Throwable with an optional formatted message. Its stack - trace will begin with our caller's caller. Args are as described for - throwf except throwable accepts them as list rather than inline." + "Constructs a Throwable with optional cause and formatted message. Its + stack trace will begin with our caller's caller. Args are as described + for throwf except throwable accepts them as list rather than inline." [args] - (let [[class & [fmt & fmt-args]] (if (class? (first args)) - args - (cons Exception args)) - ctor-args (into-array (if fmt [(apply format fmt fmt-args)] [])) + (let [[arg] args + [class & args] (if (class? arg) args (cons Exception args)) + [arg] args + [cause & args] (if (throwable? arg) args (cons nil args)) + message (when args (apply format args)) + ctor-args (into-array Object [message cause]) throwable (Reflector/invokeConstructor class ctor-args) our-prefix "clojure.contrib.except$throwable" not-us? #(not (.startsWith (.getClassName %) our-prefix)) |