[GROOVY-3242] metaclass and curry() gives MissingMethodException

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.6-rc-1
• Fix Version/s: 1.6-rc-2, 1.5.8, 1.7-beta-1
• Environment: Java 1.6; vista sp1
• Assignee: Paul King
• Reporter: alpheratz
• Created: 29/Dec/08 16:17
• Updated: 07/Apr/15 19:13
• Resolved: 30/Dec/08 19:38

Description

Consider the following:

===
def nonCurryClosure =

{delim, expected -> .... }

String.metaClass.fastSplit = nonCurryClosure
def c = nonCurryClosure.curry(",", 4)
String.metaClass.fastSplitComma4 =

{ c.delegate = delegate; c() }

===

IMHO, the need to reset 'delegate' in fastSplitComma4's closure is wrong.

As the doco says:

"When the curry() method is called on a closure instance with one or more arguments, a copy of the
closure is first made."

It seems as though the copy is rather inexact in this circumstance.

There's an associated thread in groovy-user: http://markmail.org/message/n6vn64behmvg4fkq?q=metaclass+and+curry()+gives+MissingMethodException

I started off with the following:

===
package au.com.transentia.utils.test

public class FastSplitTest extends GroovyTestCase {

void setUp() {
String.metaClass.fastSplit = {delim, expected ->
def buffer = []
try

{ StringTokenizer st = new StringTokenizer(delegate, delim); for (int i = 0; i < expected; i++) buffer[i] = st.nextToken(); return buffer.toArray(); }

catch (NoSuchElementException e)

{ throw new NoSuchElementException("Could not successfully split line: '" + delegate + "' into " + expected + " items delimited by '" + delim + "'"); }

}

String.metaClass.fastSplitComma4 = String.metaClass.fastSplit.curry(",", 4)
}

void testSplit()

{ assertArrayEquals(['this', 'is', 'a', 'test'].toArray(), "this,is,a,test".fastSplit(",", 4)) }

void testCurried()

{ assertArrayEquals(['this', 'is', 'a', 'test'].toArray(), "this,is,a,test".fastSplitComma4()) }

}
===

This gives:
===
"C:\Program Files\Java\jdk1.6.0_11\bin\java" -Didea.launcher.port=7551
"-Didea.launcher.bin.path=C:\Program Files\JetBrains\IntelliJ IDEA
8.0.1\bin" -Dfile.encoding=windows-1252 -classpath
"C:\DEVTOOLS\groovy-1.6-RC-1\embeddable\groovy-all-1.6-RC-1.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\charsets.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\deploy.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\javaws.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\jce.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\jsse.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\management-agent.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\plugin.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\resources.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\rt.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\ext\dnsns.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\ext\localedata.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\ext\sunjce_provider.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\ext\sunmscapi.jar;C:\Program
Files\Java\jdk1.6.0_11\jre\lib\ext\sunpkcs11.jar;C:\DEVELOPMENT\IntelliJ\FB\
out\production\FB;C:\DEVTOOLS\commons-lang-2.4\commons-lang-2.4.jar;C:\DEVTO
OLS\groovy-1.6-RC-1\lib\junit-3.8.2.jar;C:\Program Files\JetBrains\IntelliJ
IDEA 8.0.1\lib\idea_rt.jar" com.intellij.rt.execution.application.AppMain
com.intellij.rt.execution.junit.JUnitStarter -ideVersion5
au.com.transentia.utils.test.FastSplitTest

groovy.lang.MissingMethodException: No signature of method:
groovy.lang.ExpandoMetaClass$ExpandoMetaProperty.curry() is applicable for
argument types: (java.lang.String, java.lang.Integer) values:

{,, 4}
at
org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapt
er.java:54)
at
org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSit
e.java:51)
at
org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray
.java:43)
at
org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.
java:116)
at
org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.
java:128)
at
au.com.transentia.utils.test.FastSplitTest.setUp(FastSplitTest.groovy:21)
at
com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:40)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39
)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl
.java:25)
at
com.intellij.rt.execution.application.AppMain.main(AppMain.java:90)


groovy.lang.MissingMethodException: No signature of method:
groovy.lang.ExpandoMetaClass$ExpandoMetaProperty.curry() is applicable for
argument types: (java.lang.String, java.lang.Integer) values: {,, 4}

at
org.codehaus.groovy.runtime.ScriptBytecodeAdapter.unwrap(ScriptBytecodeAdapt
er.java:54)
at
org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSit
e.java:51)
at
org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.
java:128)
at
au.com.transentia.utils.test.FastSplitTest.setUp(FastSplitTest.groovy:21)
at
com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:40)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39
)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl
.java:25)
at
com.intellij.rt.execution.application.AppMain.main(AppMain.java:90)

Process finished with exit code -1
===