variables created within the closure fail to be visible outside as local variables

The following code from the User Guide should work:

count = 0
[1, 2, 3, 4].each { count += it; last = it }
println("the sum is ${count} and the last item was ${last}")


but gives:

[]
[]
Caught: java.lang.NullPointerException
java.lang.NullPointerException
at test$1.doCall(test.groovy:2)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.codehaus.groovy.runtime.ReflectionMetaMethod.invoke(ReflectionMet
aMethod.java:56)
at groovy.lang.Closure.call(Closure.java:195)
at org.codehaus.groovy.runtime.DefaultGroovyMethods.each(DefaultGroovyMe
thods.java:283)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.codehaus.groovy.runtime.ReflectionMetaMethod.invoke(ReflectionMet
aMethod.java:56)
at org.codehaus.groovy.runtime.NewStaticMetaMethod.invoke(NewStaticMetaM
ethod.java:100)
at groovy.lang.MetaClass.doMethodInvoke(MetaClass.java:846)
at groovy.lang.MetaClass.invokeMethod(MetaClass.java:268)
at org.codehaus.groovy.runtime.Invoker.invokeMethod(Invoker.java:130)
at org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.
java:101)
at test.run(test.groovy:2)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.codehaus.groovy.runtime.ReflectionMetaMethod.invoke(ReflectionMet
aMethod.java:56)
at groovy.lang.MetaClass.doMethodInvoke(MetaClass.java:846)
at groovy.lang.MetaClass.invokeMethod(MetaClass.java:268)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.codehaus.groovy.runtime.ReflectionMetaMethod.invoke(ReflectionMet
aMethod.java:56)
at groovy.lang.MetaClass.doMethodInvoke(MetaClass.java:846)
at groovy.lang.MetaClass.invokeMethod(MetaClass.java:268)
at org.codehaus.groovy.runtime.Invoker.invokeMethod(Invoker.java:130)
at org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.
java:101)
at test.invokeMethod(test.groovy)
at org.codehaus.groovy.runtime.Invoker.invokeMethod(Invoker.java:117)
at org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.
java:101)
at org.codehaus.groovy.runtime.InvokerHelper.runScript(InvokerHelper.jav
a:332)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.codehaus.groovy.runtime.ReflectionMetaMethod.invoke(ReflectionMet
aMethod.java:56)
at groovy.lang.MetaClass.doMethodInvoke(MetaClass.java:846)
at groovy.lang.MetaClass.invokeStaticMethod(MetaClass.java:329)
at org.codehaus.groovy.runtime.Invoker.invokeMethod(Invoker.java:124)
at org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.
java:101)
at test.main(test.groovy)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at org.codehaus.groovy.runtime.ReflectionMetaMethod.invoke(ReflectionMet
aMethod.java:56)
at groovy.lang.MetaClass.doMethodInvoke(MetaClass.java:846)
at groovy.lang.MetaClass.invokeStaticMethod(MetaClass.java:329)
at org.codehaus.groovy.runtime.Invoker.invokeMethod(Invoker.java:124)
at org.codehaus.groovy.runtime.InvokerHelper.invokeMethod(InvokerHelper.
java:101)
at groovy.lang.GroovyShell.run(GroovyShell.java:183)
at groovy.lang.GroovyShell.main(GroovyShell.java:88)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.
java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAcces
sorImpl.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)


If we include the initialization of 'last' everything works:

count = 0
last = 0
[1, 2, 3, 4].each { count += it; last = it }
println("the sum is ${count} and the last item was ${last}")