Foo.java

// Generated from foo.mirah
package org.mirah;
public class Foo extends java.lang.Object {
  @hudson.Extension()
  private java.lang.String extension;
  public static void main(java.lang.String[] argv) {
    this.extension = "fooooo";
  public java.lang.String getExtension() {
    return "helo";
  }
}

foo.mirah

package org.mirah
import hudson.Extension

class Foo
  $Extension
  @extension = 'fooooo'

  def getExtension
    "helo"
  end
end

trace

[INFO] [clean:clean {execution: default-clean}]
[INFO] Deleting directory /Users/david/dev/mirah-foo/target
[INFO] [resources:resources {execution: default-resources}]
[WARNING] Using platform encoding (MacRoman actually) to copy filtered resources, i.e. build is platform dependent!
[INFO] skip non existing resourceDirectory /Users/david/dev/mirah-foo/src/main/resources
[INFO] [compiler:compile {execution: default-compile}]
[INFO] No sources to compile
[INFO] [mirah:compile {execution: default}]
* [AST] [Noop] Noop resolved!
* [Duby::Typer] New type defined: 'Foo' < ''
* [AST] [Noop] Noop resolved!
* [AST] [String] String("fooooo") resolved!
* [Duby::Typer] Learned field type under ClassDefinition(Foo) : extension = Type(java.lang.String)
* [AST] [FieldAssignment] FieldAssignment(extension) resolved!
* [AST] [Arguments] Arguments resolved!
* [JVM::Types] No exact match for org.mirah.Foo.getExtension()
* [JVM::Types] Beginning JLS phase 1 search with params ()
* [JVM::Types] Attempting instance field lookup for 'getExtension' on class Type(org.mirah.Foo)
* [JVM::Types] Failed to locate method org.mirah.Foo.getExtension()
* [AST] [String] String("helo") resolved!
* [Duby::Typer] Learned method getExtension () on Type(org.mirah.Foo) = Type(java.lang.String)
* [AST] [MethodDefinition] MethodDefinition(getExtension) resolved!
* [AST] [Body] Body resolved!
* [AST] [Body] Body resolved!
* [AST] [ClassDefinition] ClassDefinition(Foo) resolved!
* [AST] [Body] Body resolved!
* [AST] [Script] Script resolved!
* [Duby::Typer] Entering type inference cycle
* [Duby::Typer] [Cycle 0]: Started...
* [Duby::Typer] [Cycle 0]:  Resolved all types, exiting
* [Duby::Typer] [Cycle 0]: Complete!
[Script
 body:
  Body
   Noop
   Import(Extension = hudson.Extension)
   ClassDefinition(Foo)
    body:
     Body
      Body
       Noop
       FieldAssignment(extension)
        value:
         String("fooooo")
       MethodDefinition(getExtension)
        signature:
        {:return=>#<Duby::JVM::Types::StringType java.lang.String>}
        arguments:
         Arguments
        body:
         String("helo")]
* [Duby::Compiler::JVM] Starting main method
* [Duby::Compiler::JVM] Starting new method getExtension
* [Duby::Compiler::JVM] Method getExtension complete!
* [Duby::Compiler::JVM] Class org/mirah/Foo complete (301)
* [Duby::Compiler::JVM] Class org/mirah/Foo complete (303)
* [Duby::Compiler::JVM] Main method complete!
* [Duby::Compiler::JVM] Generating source files...
* [Duby::Compiler::JVM]   Foo
* [Duby::Compiler::JVM] ...done!