1 files changed, 46 insertions, 29 deletions
diff --git a/src/clojure/contrib/except/except.clj b/src/clojure/contrib/except/except.clj
index d6dd62d9..e65044dc 100644
--- a/src/clojure/contrib/except/except.clj
+++ b/src/clojure/contrib/except/except.clj
@@ -8,55 +8,72 @@
 ;;
 ;;  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.
+;;
 ;;  scgilardi (gmail)
 ;;  Created 07 July 2008
 
 (ns clojure.contrib.except
   (:import (clojure.lang Reflector)))
 
-(declare throw-formatted)
+(declare throwable)
 
 (defn throwf
-  "Throws a formatted Exception or Error with an optional message formatted
-  like clojure/printf. All arguments are optional:
+  "Throws an Exception or Error with an optional message formatted using
+  clojure/format. All arguments are optional:
 
       class? format? format-args*
 
-  - class defaults to Exception
+  - class defaults to Exception, if present it must name a kind of
+    Throwable
   - format is a format string for clojure/format
-  - format-args are objects that correspond format specifiers in format."
+  - format-args are objects that correspond to format specifiers in
+    format."
   [& args]
-  (apply throw-formatted "clojure.contrib.except.throwf" args))
+  (throw (throwable args)))
 
 (defn throw-if
-  "Throws a formatted Exception or Error if test is true. args are those
-  documented for throwf."
+  "Throws an Exception or Error if test is true. args are those documented
+  for throwf."
   [test & args]
   (when test
-    (apply throw-formatted "clojure.contrib.except.throw_if" args)))
+    (throw (throwable args))))
 
 ;; throw-if-not is synonymous with assert, but clojure/assert exists
 
 (defn throw-if-not
-  "Throws a formatted Exception or Error if test is false. args are those
-  documented for throwf."
+  "Throws an Exception or Error if test is false. args are those documented
+  for throwf."
   [test & args]
   (when-not test
-    (apply throw-formatted "clojure.contrib.except.throw_if_not" args)))
-
-(defn- throw-formatted
-  "Internal helper for formatted exceptions. It builds the formatted message,
-  creates the exception object, and edits the exception's stack trace to
-  exclude frames that are internal to our implementation. The stack trace
-  will start with the line in the caller that contains the throwf,
-  throw-if, or throw-if-not call."
-  [fn-prefix & args]
-  (let [[class & [fmt & fmt-args]]
-         (if (class? (first args)) args (cons Exception args))
-        args (into-array (if fmt [(apply format fmt fmt-args)] []))
-        exception (Reflector/invokeConstructor class args)
-        raw-trace (.getStackTrace exception)
-        not-our-fn? #(not (.startsWith (.getClassName %) fn-prefix))
-        trace (into-array (rrest (drop-while not-our-fn? raw-trace)))]
-    (.setStackTrace exception trace)
-    (throw exception)))
+    (throw (throwable args))))
+
+(defn throw-arg
+  "Throws an IllegalArgumentException. All arguments are optional:
+
+        format? format-args*
+
+  - format is a format string for clojure/format
+  - format-args are objects that correspond to format specifiers in
+    format."
+  [& args]
+  (throw (throwable (cons IllegalArgumentException args))))
+
+(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."
+  [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)] []))
+        throwable (Reflector/invokeConstructor class ctor-args)
+        our-prefix "clojure.contrib.except.throwable"
+        not-us? #(not (.startsWith (.getClassName %) our-prefix))
+        raw-trace (.getStackTrace throwable)
+        edited-trace (into-array (drop 3 (drop-while not-us? raw-trace)))]
+    (.setStackTrace throwable edited-trace)
+    throwable))