New: + CPException raise:format:.

This method allows the exception reason to be a formatted string with parameter replacement.

Foundation/CPException.j

@@ -71,6 +71,22 @@ if (input == nil)
     [[self exceptionWithName:aName reason:aReason userInfo:nil] raise];
 }
 
+/*!
+    Raises an exception with a name and a formatted reason.
+    @param aName the name of the exception to raise
+    @param aFormat the reason for the exception in sprintf style
+    @param ... the arguments for the sprintf format
+*/
++ (void)raise:(CPString)aName format:(CPString)aFormat, ...
+{
+    if (!aFormat)
+        [CPException raise:CPInvalidArgumentException
+                    reason:"raise:format: the format can't be 'nil'"];
+
+    var aReason = ObjectiveJ.sprintf.apply(this, Array.prototype.slice.call(arguments, 3));
+    [[self exceptionWithName:aName reason:aReason userInfo:nil] raise];
+}
+
 /*!
     Creates an exception with a name, reason and user info.
     @param aName the name of the exception

Tests/Foundation/CPExceptionTest.j

@@ -27,6 +27,22 @@
     [self assertThrows:function(){[CPException raise:@"CPGenericException" reason:@"Margins must be positive"];}];
 }
 
+- (void)testRaise_format_
+{
+    var success = NO;
+    try
+    {
+        [CPException raise:CPGenericException format:@"Expected %.2f for %s", 0.789, "hello"];
+    }
+    catch (anException)
+    {
+        success = YES;
+        [self assert:CPGenericException equals:[anException name]];
+        [self assert:@"Expected 0.79 for hello" equals:[anException reason]];
+    }
+    [self assertTrue:success];
+}
+
 - (void)testName
 {
     [self assert:[exception name] equals:@"CPGenericException"];