[GROOVY-661] unexpected behavior with adding list to a number

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0-beta-8
• Fix Version/s: 1.0-beta-8
• Component/s: groovy-jdk
• Environment: tested on Win2k
• Assignee: Unassigned
• Reporter: Jochen Theodorou
• Created: 04/Nov/04 09:51
• Updated: 08/Dec/04 13:15
• Resolved: 08/Dec/04 13:15

Description

just try

print(5+[1,2])

it results in null. I think that's nothing you would expect. But may be it's not a good idea to just make a new list [5,1,2]. So I suggest to throw an UnsupportedOperationException. This should always be the case when no operation is found, but as I'm new to the code of groovy and I didn't found the correct place to do this I will give only a fix for this special case:

Index: groovy-core/src/main/org/codehaus/groovy/runtime/DefaultGroovyMethods.java
===================================================================
RCS file: /home/projects/groovy/scm/groovy/groovy-core/src/main/org/codehaus/groovy/runtime/DefaultGroovyMethods.java,v
retrieving revision 1.122
diff -u -r1.122 DefaultGroovyMethods.java
— groovy-core/src/main/org/codehaus/groovy/runtime/DefaultGroovyMethods.java 5 Oct 2004 08:53:38 -0000 1.122
+++ groovy-core/src/main/org/codehaus/groovy/runtime/DefaultGroovyMethods.java 4 Nov 2004 14:38:23 -0000
@@ -1719,6 +1719,20 @@
return answer;
}

+
+ /**
+ * Catch the unwanted case an Object and a Collection with the Collection on
+ * the right side.
+ *
+ * @param left an object
+ * @param right a Collection
+ * @return nothing
+ * @throws always an UnsupportedOperationException
+ */
+ public static List plus(Object left, Collection right)

{ + throw new UnsupportedOperationException("Left side has to be a list but was "+left.getClass().getName()); + }

+
/**

• Create a List composed of the same elements repeated a certain number of times.
  *