[GROOVY-3613] Need to supply hand-crafted constructor for enum having >1 field

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Won't Fix
• Affects Version/s: 1.6.3
• Fix Version/s: 1.7.5, 1.8-beta-2
• Component/s: Compiler
• Environment: Win7 / java 1.6.0_14
• Assignee: Roshan Dawrani
• Reporter: alpheratz
• Created: 06/Jul/09 05:41
• Updated: 15/Dec/10 22:19
• Resolved: 16/Sep/10 07:47

Description

enum T {
  ALPHA(1, 2),
  BETA(3, 4),
  GAMMA(5, 6)
	
  def x
  def y
	
  @Override
  public String toString() {
    "{x: $x, y: $y}"
  }
}
	
println T.ALPHA

Didn’t work! Imagine my surprise! Gives:

Caught: java.lang.ExceptionInInitializerError
	at Test.class$(Test.groovy)
	at Test.$get$$class$T(Test.groovy)
	at Test.run(Test.groovy:20)

I tried a Groovy style constructor with named parameters:

enum T {
  ALPHA(x: 1, y: 2),
  BETA(x: 3, y: 4),
  GAMMA(x: 5, y: 6)
	
  def x
  def y
	
  @Override
  public String toString() {
    "{x: $x, y: $y}"
  }
}
	
println T.ALPHA

Didn’t work. One gets an almighty compiler error:

Information:Compilation completed with 1 error and 0 warnings
Information:1 error
Information:0 warnings
Error:BUG! exception in phase 'class generation' in source unit 'C:UsersBobDesktopAlexMaterialsrcTest.groovy' MapEntryExpression should not be visited here at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitMapEntryExpression(AsmClassGenerator.java:3058)at
 org.codehaus.groovy.ast.expr.MapEntryExpression.visit(MapEntryExpression.java:37)at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitAndAutoboxBoolean(AsmClassGenerator.java:4029)at
 org.codehaus.groovy.classgen.AsmClassGenerator.makeCallSite(AsmClassGenerator.java:1955)at
 org.codehaus.groovy.classgen.AsmClassGenerator.makeCall(AsmClassGenerator.java:1789)at
 org.codehaus.groovy.classgen.AsmClassGenerator.makeCall(AsmClassGenerator.java:1775)at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitStaticMethodCallExpression(AsmClassGenerator.java:2334)at
 org.codehaus.groovy.ast.expr.StaticMethodCallExpression.visit(StaticMethodCallExpression.java:43)at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitAndAutoboxBoolean(AsmClassGenerator.java:4029)at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitCastExpression(AsmClassGenerator.java:1701)at
 org.codehaus.groovy.classgen.AsmClassGenerator.assignmentCastAndVisit(AsmClassGenerator.java:3968)at
 org.codehaus.groovy.classgen.AsmClassGenerator.evaluateEqual(AsmClassGenerator.java:3920)at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitBinaryExpression(AsmClassGenerator.java:1324)at
 org.codehaus.groovy.ast.expr.BinaryExpression.visit(BinaryExpression.java:49)at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitAndAutoboxBoolean(AsmClassGenerator.java:4029)at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitExpressionStatement(AsmClassGenerator.java:1305)at
 org.codehaus.groovy.ast.stmt.ExpressionStatement.visit(ExpressionStatement.java:40)at
 org.codehaus.groovy.ast.CodeVisitorSupport.visitBlockStatement(CodeVisitorSupport.java:38)at
 org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitBlockStatement(ClassCodeVisitorSupport.java:129)at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitBlockStatement(AsmClassGenerator.java:665)at
 org.codehaus.groovy.ast.stmt.BlockStatement.visit(BlockStatement.java:52)at
 org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClassCodeContainer(ClassCodeVisitorSupport.java:73)at
 org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitConstructorOrMethod(ClassCodeVisitorSupport.java:80)at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitStdMethod(AsmClassGenerator.java:542)at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitConstructorOrMethod(AsmClassGenerator.java:518)at
 org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitMethod(ClassCodeVisitorSupport.java:88)at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitMethod(AsmClassGenerator.java:622)at
 org.codehaus.groovy.ast.ClassNode.visitContents(ClassNode.java:1004)at
 org.codehaus.groovy.ast.ClassCodeVisitorSupport.visitClass(ClassCodeVisitorSupport.java:48)at
 org.codehaus.groovy.classgen.AsmClassGenerator.visitClass(AsmClassGenerator.java:243)at
 org.codehaus.groovy.control.CompilationUnit$10.call(CompilationUnit.java:717)at
 org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:924)at
 org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:462)at
 org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:443)at
 org.jetbrains.groovy.compiler.rt.MyCompilationUnits.compile(MyCompilationUnits.java:52)at
 org.jetbrains.groovy.compiler.rt.GroovycRunner.main(GroovycRunner.java:188)

It was just a guess/attempt...but was sort of 'logical'.

One HAS to supply a constructor:

enum T {
  ALPHA(1, 2),
  BETA(3, 4),
  GAMMA(5, 6)
	
  T(x, y) {
    this.x = x
    this.y = y
  }
	
  def x
  def y
	
  @Override
  public String toString() {
    "{x: $x, y: $y}"
  }
}
	
println T.ALPHA

It flies! Viz:

{x: 1, y: 2}

SO: a minor problem, with a workaround...but a surprise, nonetheless.

Not very 'groovy' though!

And not documented

I have written up a bit more (some alternative tests) at http://www.transentia.com.au/flatpress/index.php/2009/07/06/the-perils-of-being-a-smarty-pants/

Is this a regression of GROOVY-3276 ?

Issue Links

• relates to: GROOVY-4219 Error during class generation for simple java/groovy program
• relates to: GROOVY-4582 allow named argument list expressions for enum field init code