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Given the following Xtend class: public class Foo { def foo() { switch null { case null : [Object it|it] case null : [Integer it|it] } } } The following error is logged to the console and nothing is being compiled. Also note that there are no errors (not in the error log either) or markers in the workbench. I.e. the user can't tell something went wrong. 132198 [Worker-9] ERROR org.eclipse.xtext.builder.impl.XtextBuilder - a closure definition does not cause any side-effects java.lang.IllegalArgumentException: a closure definition does not cause any side-effects at org.eclipse.xtext.xbase.compiler.XbaseCompiler._toJavaStatement(XbaseCompiler.java:472) at sun.reflect.GeneratedMethodAccessor92.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.eclipse.xtext.util.PolymorphicDispatcher.invoke(PolymorphicDispatcher.java:291) at org.eclipse.xtext.xbase.compiler.AbstractXbaseCompiler.internalToJavaStatement(AbstractXbaseCompiler.java:137) at org.eclipse.xtext.xbase.compiler.XbaseCompiler._toJavaStatement(XbaseCompiler.java:428) at sun.reflect.GeneratedMethodAccessor83.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.eclipse.xtext.util.PolymorphicDispatcher.invoke(PolymorphicDispatcher.java:291) at org.eclipse.xtext.xbase.compiler.AbstractXbaseCompiler.internalToJavaStatement(AbstractXbaseCompiler.java:137) at org.eclipse.xtext.xbase.compiler.XbaseCompiler._toJavaStatement(XbaseCompiler.java:53) at sun.reflect.GeneratedMethodAccessor79.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.eclipse.xtext.util.PolymorphicDispatcher.invoke(PolymorphicDispatcher.java:291) at org.eclipse.xtext.xbase.compiler.AbstractXbaseCompiler.internalToJavaStatement(AbstractXbaseCompiler.java:137) at org.eclipse.xtext.xbase.compiler.AbstractXbaseCompiler.compile(AbstractXbaseCompiler.java:90) at org.eclipse.xtext.xbase.compiler.JvmModelGenerator.generateBody(JvmModelGenerator.java:739) at org.eclipse.xtext.xbase.compiler.JvmModelGenerator._generateMember(JvmModelGenerator.java:497) at org.eclipse.xtext.xbase.compiler.JvmModelGenerator.generateMember(JvmModelGenerator.java:1123) at org.eclipse.xtext.xbase.compiler.JvmModelGenerator$1.apply(JvmModelGenerator.java:166) at org.eclipse.xtext.xbase.compiler.JvmModelGenerator$1.apply(JvmModelGenerator.java:1) at org.eclipse.xtext.xbase.lib.IterableExtensions$FunctionDelegate.apply(IterableExtensions.java:808) at com.google.common.collect.Lists$TransformingRandomAccessList.get(Lists.java:431) at java.util.AbstractList$Itr.next(AbstractList.java:345) at com.google.common.collect.Iterators$7.computeNext(Iterators.java:602) at com.google.common.collect.AbstractIterator.tryToComputeNext(AbstractIterator.java:135) at com.google.common.collect.AbstractIterator.hasNext(AbstractIterator.java:130) at org.eclipse.xtext.xbase.compiler.JvmModelGenerator.generateBody(JvmModelGenerator.java:179) at org.eclipse.xtext.xbase.compiler.JvmModelGenerator.generateType(JvmModelGenerator.java:95) at org.eclipse.xtext.xbase.compiler.JvmModelGenerator._internalDoGenerate(JvmModelGenerator.java:86) at org.eclipse.xtext.xbase.compiler.JvmModelGenerator.internalDoGenerate(JvmModelGenerator.java:1098) at org.eclipse.xtext.xbase.compiler.JvmModelGenerator.doGenerate(JvmModelGenerator.java:75) at org.eclipse.xtext.builder.BuilderParticipant.handleChangedContents(BuilderParticipant.java:208) at org.eclipse.xtext.builder.BuilderParticipant.build(BuilderParticipant.java:154) at org.eclipse.xtext.builder.impl.RegistryBuilderParticipant.build(RegistryBuilderParticipant.java:60) at org.eclipse.xtext.builder.impl.XtextBuilder.doBuild(XtextBuilder.java:160) at org.eclipse.xtext.builder.impl.XtextBuilder.incrementalBuild(XtextBuilder.java:141) at org.eclipse.xtext.builder.impl.XtextBuilder.build(XtextBuilder.java:91) at org.eclipse.core.internal.events.BuildManager$2.run(BuildManager.java:627) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:170) at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:201) at org.eclipse.core.internal.events.BuildManager$1.run(BuildManager.java:253) at org.eclipse.core.runtime.SafeRunner.run(SafeRunner.java:42) at org.eclipse.core.internal.events.BuildManager.basicBuild(BuildManager.java:256) at org.eclipse.core.internal.events.BuildManager.basicBuildLoop(BuildManager.java:309) at org.eclipse.core.internal.events.BuildManager.build(BuildManager.java:341) at org.eclipse.core.internal.events.AutoBuildJob.doBuild(AutoBuildJob.java:140) at org.eclipse.core.internal.events.AutoBuildJob.run(AutoBuildJob.java:238) at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)
The problem is that Xtend is unable to calculate a common type for [Object it|it] and [Integer it|it]. But I'd expect it to calculate something like (? extends Object)=>(? extends Object) (not legal Xtend). A workaround is to define the function as: def <T extends Object> (T)=>T foo() { switch null { case null : [Object it|it] as (T)=>T case null : [Integer it|it] as (T)=>T } }
pushed to master
Closing all bugs that were set to RESOLVED before Neon.0
