The !. operator will not work on java.lang.System?

saltnlight5 · November 24, 2012, 5:13pm

Hi, is this compile error intended? So is this mean "!!." will only work for instance variable only?

fun main(args: Array<String>) {
     val p = System!!.getProperties()
     println(p)
}

output>

EXCEPTION: java.lang.UnsupportedOperationException: Only member lookup is allowed on a namespace type System

  at org.jetbrains.jet.lang.types.NamespaceType.throwException(NamespaceType.java:55)

  at org.jetbrains.jet.lang.types.NamespaceType.isNullable(NamespaceType.java:67)

  at org.jetbrains.jet.lang.types.TypeUtils.makeNullableAsSpecified(TypeUtils.java:91)

  at org.jetbrains.jet.lang.types.TypeUtils.makeNotNullable(TypeUtils.java:86)

  at org.jetbrains.jet.lang.types.checker.TypeCheckingProcedure.isSubtypeOf(TypeCheckingProcedure.java:165)

  at org.jetbrains.jet.lang.types.checker.JetTypeChecker.isSubtypeOf(JetTypeChecker.java:38)

  at org.jetbrains.jet.lang.types.TypeUtils.equalTypes(TypeUtils.java:457)

  at org.jetbrains.jet.lang.resolve.calls.autocasts.DataFlowValueFactory.createDataFlowValue(DataFlowValueFactory.java:47)

  at org.jetbrains.jet.lang.types.expressions.BasicExpressionTypingVisitor.isKnownToBeNotNull(BasicExpressionTypingVisitor.java:1025)

  at org.jetbrains.jet.lang.types.expressions.BasicExpressionTypingVisitor.visitExclExclExpression(BasicExpressionTypingVisitor.java:996)

  at org.jetbrains.jet.lang.types.expressions.BasicExpressionTypingVisitor.visitUnaryExpression(BasicExpressionTypingVisitor.java:909)

  at org.jetbrains.jet.lang.types.expressions.BasicExpressionTypingVisitor.visitUnaryExpression(BasicExpressionTypingVisitor.java:892)

  at org.jetbrains.jet.lang.types.expressions.BasicExpressionTypingVisitor.visitUnaryExpression(BasicExpressionTypingVisitor.java:65)

  at org.jetbrains.jet.lang.psi.JetVisitor.visitPostfixExpression(JetVisitor.java:177)

  at org.jetbrains.jet.lang.psi.JetPostfixExpression.accept(JetPostfixExpression.java:44)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.visitJetElement(ExpressionTypingVisitorDispatcher.java:230)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.visitJetElement(ExpressionTypingVisitorDispatcher.java:37)

  at org.jetbrains.jet.lang.psi.JetVisitor.visitExpression(JetVisitor.java:148)

  at org.jetbrains.jet.lang.psi.JetVisitor.visitUnaryExpression(JetVisitor.java:181)

  at org.jetbrains.jet.lang.psi.JetVisitor.visitPostfixExpression(JetVisitor.java:177)

  at org.jetbrains.jet.lang.psi.JetPostfixExpression.accept(JetPostfixExpression.java:44)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.getTypeInfo(ExpressionTypingVisitorDispatcher.java:125)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.getTypeInfo(ExpressionTypingVisitorDispatcher.java:93)

  at org.jetbrains.jet.lang.types.expressions.BasicExpressionTypingVisitor.visitQualifiedExpression(BasicExpressionTypingVisitor.java:651)

  at org.jetbrains.jet.lang.types.expressions.BasicExpressionTypingVisitor.visitQualifiedExpression(BasicExpressionTypingVisitor.java:65)

  at org.jetbrains.jet.lang.psi.JetVisitor.visitDotQualifiedExpression(JetVisitor.java:261)

  at org.jetbrains.jet.lang.psi.JetDotQualifiedExpression.accept(JetDotQualifiedExpression.java:37)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.visitJetElement(ExpressionTypingVisitorDispatcher.java:230)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.visitJetElement(ExpressionTypingVisitorDispatcher.java:37)

  at org.jetbrains.jet.lang.psi.JetVisitor.visitExpression(JetVisitor.java:148)

  at org.jetbrains.jet.lang.psi.JetVisitor.visitQualifiedExpression(JetVisitor.java:253)

  at org.jetbrains.jet.lang.psi.JetVisitor.visitDotQualifiedExpression(JetVisitor.java:261)

  at org.jetbrains.jet.lang.psi.JetDotQualifiedExpression.accept(JetDotQualifiedExpression.java:37)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.getTypeInfo(ExpressionTypingVisitorDispatcher.java:125)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.getTypeInfo(ExpressionTypingVisitorDispatcher.java:93)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingServices.getTypeInfo(ExpressionTypingServices.java:125)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingServices.getType(ExpressionTypingServices.java:130)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingServices.safeGetType(ExpressionTypingServices.java:113)

  at org.jetbrains.jet.lang.resolve.DescriptorResolver$2.compute(DescriptorResolver.java:994)

  at org.jetbrains.jet.lang.resolve.DescriptorResolver$2.compute(DescriptorResolver.java:991)

  at org.jetbrains.jet.util.lazy.LazyValue.get(LazyValue.java:48)

  at org.jetbrains.jet.lang.resolve.DescriptorResolver.getVariableType(DescriptorResolver.java:1001)

  at org.jetbrains.jet.lang.resolve.DescriptorResolver.resolveLocalVariableDescriptor(DescriptorResolver.java:754)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorForStatements.visitProperty(ExpressionTypingVisitorForStatements.java:110)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorForStatements.visitProperty(ExpressionTypingVisitorForStatements.java:50)

  at org.jetbrains.jet.lang.psi.JetProperty.accept(JetProperty.java:60)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.getTypeInfo(ExpressionTypingVisitorDispatcher.java:125)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.getTypeInfo(ExpressionTypingVisitorDispatcher.java:100)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingServices.getBlockReturnedTypeWithWritableScope(ExpressionTypingServices.java:344)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingServices.getBlockReturnedType(ExpressionTypingServices.java:206)

  at org.jetbrains.jet.lang.types.expressions.BasicExpressionTypingVisitor.visitBlockExpression(BasicExpressionTypingVisitor.java:634)

  at org.jetbrains.jet.lang.types.expressions.BasicExpressionTypingVisitor.visitBlockExpression(BasicExpressionTypingVisitor.java:630)

  at org.jetbrains.jet.lang.types.expressions.BasicExpressionTypingVisitor.visitBlockExpression(BasicExpressionTypingVisitor.java:65)

  at org.jetbrains.jet.lang.psi.JetBlockExpression.accept(JetBlockExpression.java:50)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.visitJetElement(ExpressionTypingVisitorDispatcher.java:230)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.visitJetElement(ExpressionTypingVisitorDispatcher.java:37)

  at org.jetbrains.jet.lang.psi.JetVisitor.visitExpression(JetVisitor.java:148)

  at org.jetbrains.jet.lang.psi.JetVisitor.visitBlockExpression(JetVisitor.java:277)

  at org.jetbrains.jet.lang.psi.JetBlockExpression.accept(JetBlockExpression.java:50)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.getTypeInfo(ExpressionTypingVisitorDispatcher.java:125)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.getTypeInfo(ExpressionTypingVisitorDispatcher.java:93)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingVisitorDispatcher.getTypeInfo(ExpressionTypingVisitorDispatcher.java:98)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingServices.checkFunctionReturnType(ExpressionTypingServices.java:181)

  at org.jetbrains.jet.lang.types.expressions.ExpressionTypingServices.checkFunctionReturnType(ExpressionTypingServices.java:159)

  at org.jetbrains.jet.lang.resolve.BodyResolver.resolveFunctionBody(BodyResolver.java:513)

  at org.jetbrains.jet.lang.resolve.BodyResolver.resolveFunctionBodies(BodyResolver.java:497)

  at org.jetbrains.jet.lang.resolve.BodyResolver.resolveBehaviorDeclarationBodies(BodyResolver.java:131)

  at org.jetbrains.jet.lang.resolve.BodyResolver.resolveBodies(BodyResolver.java:141)

  at org.jetbrains.jet.lang.resolve.TopDownAnalyzer.doProcess(TopDownAnalyzer.java:134)

  at org.jetbrains.jet.lang.resolve.TopDownAnalyzer.analyzeFiles(TopDownAnalyzer.java:259)

  at org.jetbrains.jet.lang.resolve.java.AnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration(AnalyzerFacadeForJVM.java:204)

  at org.jetbrains.jet.lang.resolve.java.AnalyzerFacadeForJVM.analyzeFilesWithJavaIntegration(AnalyzerFacadeForJVM.java:186)

  at org.jetbrains.jet.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$1.invoke(KotlinToJVMBytecodeCompiler.java:317)

  at org.jetbrains.jet.cli.jvm.compiler.KotlinToJVMBytecodeCompiler$1.invoke(KotlinToJVMBytecodeCompiler.java:313)

  at org.jetbrains.jet.cli.common.messages.AnalyzerWithCompilerReport.analyzeAndReport(AnalyzerWithCompilerReport.java:212)

  at org.jetbrains.jet.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.analyze(KotlinToJVMBytecodeCompiler.java:312)

  at org.jetbrains.jet.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.analyzeAndGenerate(KotlinToJVMBytecodeCompiler.java:292)

  at org.jetbrains.jet.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.analyzeAndGenerate(KotlinToJVMBytecodeCompiler.java:273)

  at org.jetbrains.jet.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileBunchOfSources(KotlinToJVMBytecodeCompiler.java:187)

  at org.jetbrains.jet.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.java:141)

  at org.jetbrains.jet.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.java:53)

  at org.jetbrains.jet.cli.common.CLICompiler.exec(CLICompiler.java:117)

  at org.jetbrains.jet.cli.jvm.K2JVMCompiler.exec(K2JVMCompiler.java:179)

  at org.jetbrains.jet.cli.jvm.K2JVMCompiler.exec(K2JVMCompiler.java:53)

  at org.jetbrains.jet.cli.common.CLICompiler.exec(CLICompiler.java:47)

  at org.jetbrains.jet.cli.common.CLICompiler.doMainNoExit(CLICompiler.java:160)

  at org.jetbrains.jet.cli.common.CLICompiler.doMain(CLICompiler.java:151)

  at org.jetbrains.jet.cli.jvm.K2JVMCompiler.main(K2JVMCompiler.java:57)
exec() finished with INTERNAL_ERROR return code

komu · November 25, 2012, 12:29am

I guess that you want to say this instead:

``

val p = System.getProperties()!!

saltnlight5 · November 26, 2012, 8:43pm

Ahh, yes. Thank you Juha for pointing that out. I get confused on the usage of !! operator.

Flow · November 27, 2012, 7:56am

I think you should create a bug report for this. It should be a compiler error, not a run-time error.

youtrack.jetbrains.com

saltnlight5 · November 27, 2012, 11:08pm

Flow, the error is thrown at compile time!

Perhaps I would suggest a more shorter and more user friendly error message improvement would be nice

abreslav · November 28, 2012, 9:36am

It's a bug, please report it to the tracker. Thanks.

saltnlight5 · November 28, 2012, 3:19pm

Sure Andrey. Here http://youtrack.jetbrains.com/issue/KT-3100

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The !. operator will not work on java.lang.System?

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