[GROOVY-132] Comparison operators throw NPE, contrary to docs

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0-beta-3
• Fix Version/s: 1.0-beta-3
• Assignee: Unassigned
• Reporter: Rod Cope
• Created: 14/Jan/04 22:14
• Updated: 16/Jan/04 11:09
• Resolved: 16/Jan/04 11:09

Description

According to this page (http://groovy.codehaus.org/operators.html), the comparison operators handle nulls gracefully and avoid throwing NullPointerException. However, this only seems to be the case for ==, ===, and !=

For example:

groovy> "dog" > null
groovy>
Caught: java.lang.NullPointerException
java.lang.NullPointerException
at java.lang.String.compareTo(String.java:727)
at java.lang.String.compareTo(String.java:777)
at org.codehaus.groovy.runtime.Invoker.compareTo(Invoker.java:284)
at org.codehaus.groovy.runtime.InvokerHelper.compareGreaterThan(InvokerHelper.java:237)
at CommandLine18.run(CommandLine18.groovy)
at groovy.lang.GroovyShell.evaluate(GroovyShell.java:236)
at groovy.lang.GroovyShell.evaluate(GroovyShell.java:215)
at groovy.ui.InteractiveShell.run(InteractiveShell.java:100)
at groovy.ui.InteractiveShell.main(InteractiveShell.java:71)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.codehaus.classworlds.Launcher.launchStandard(Launcher.java:410)
at org.codehaus.classworlds.Launcher.launch(Launcher.java:344)
at org.codehaus.classworlds.Launcher.main(Launcher.java:474)

groovy> null <= 3
groovy>
Caught: groovy.lang.GroovyRuntimeException: Cannot compare values: null and right
groovy.lang.GroovyRuntimeException: Cannot compare values: null and right
at org.codehaus.groovy.runtime.Invoker.compareTo(Invoker.java:288)
at org.codehaus.groovy.runtime.InvokerHelper.compareLessThanEqual(InvokerHelper.java:233)
at CommandLine19.run(CommandLine19.groovy)
at groovy.lang.GroovyShell.evaluate(GroovyShell.java:236)
at groovy.lang.GroovyShell.evaluate(GroovyShell.java:215)
at groovy.ui.InteractiveShell.run(InteractiveShell.java:100)
at groovy.ui.InteractiveShell.main(InteractiveShell.java:71)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.codehaus.classworlds.Launcher.launchStandard(Launcher.java:410)
at org.codehaus.classworlds.Launcher.launch(Launcher.java:344)
at org.codehaus.classworlds.Launcher.main(Launcher.java:474)