Versions Compared


  • This line was added.
  • This line was removed.
  • Formatting was changed.

Considering our limited human resources and time constraints, it is hard to give definitive and accurate estimates of the milestones we are going to release.

Groovy 2.



Groovy 2.2 3 is the latest stable version of Groovy.

Feature set

  • Implicit closure coercion
  • @Memoized AST transformation to add memoization to methods
  • @Log4j2 AST transformation providing a Log4j2 logging variant
  • @BaseScript AST transformation to define the script's base script class
  • A DelegatingScript base script class to delegate all property accesses and methods calls to a delegatee object
  • Refinements to the type checking extensions (precompilation of extensions, new events, dynamic calls in static context)
  • Various GDK improvements
  • Groovysh improvements with tab completion (of imports, class names, method names, file names)


  • Groovy 2.2 finale: November 2013 (tick)

Groovy 2.3 (Q2 2014)

Feature set for consideration

  • Static traits
  • Finer-grained implicit closure coercion (depending on number and type of closure arguments)
  • Closure signature hints for APIs for better type inference and IDE tooling
  • @TailRecursive AST transformation for methods
  • Class-loading-less compilation 
    • using ASM when needed, to avoid loading/initializing classes needed during the compilation
  • Stub-less joint compilation
    to avoid various problems with the stubs and the various compilation phasesofficial support for running Groovy on JDK 8
  • traits, as a new object oriented way of composing behavior in your classes
  • new and improved AST transformations like @TailRecursive@Builder and @Sortable
  • a new NIO2 module with Path support
  • lightening fast JSON parsing and building
  • closure parameter type inference
  • a new markup template engine
  • Groovysh and GroovyConsole ease of use improvements
  • a new GroovyAssert test utility
  • more @BaseScript class capabilities, and more.


  • Groovy 2.3 beta: February-March 2014
  • Groovy 2.3 release candidates: April 2014
  • Groovy 2.3 finale: May 20142014 

Groovy 3.0 (Q4 2014)

Feature set for consideration

  • New Meta-Object Protocol dedicated 
    • to fully leverage "invoke dynamic" (method handles, class values, etc)
    • make the sedimented dynamic features more coherent
    • to fix the private visibility conundrum 
    • to shield libraries from "monkey patching" with a notion of "realm"
  • Rewrite the Groovy grammar from scratch with Antlr 4
    • in particular adapt to the Java 8 language features
      • lambdas
      • method references
      • default methods in interfaces
      • annotations on types
      • repeated annotations
  • Java 8 / JDK 8 support
    • lambdas
    • method references
    • default methods in interfaces
    • annotations on types
    • repeated annotations
    • stream API
    • date / time API


  • Groovy 3.0 alpha: end of Q1 Q3 2014
  • Groovy 3.0 betas: Q2 and Q3 2014Q4 2014 - Q1 21015
  • Groovy 3.0 release candidates: mid Q4 2014Q1 2015
  • Groovy 3.0 final: end of Q4 2014Q2 2015

Groovy 4.0 (Q4 2015)

Feature set for consideration

  • No concrete plans at the moment

Other topics we could consider for later Groovy

  • true named arguments
  • compiler related:
    • investigate making the groovyc compiler multithreaded
    • Incremental compiler
  • ability to pass expression trees / AST nodes as parameters (see C# 4's own expression tree)
  • lexical categories
  • a symbol concept, a bit like Ruby's :symbol, or like Java interned strings
  • co-routines and/or generators
  • pattern matching
  • parser combinators
  • a native template engine compiling to AST (faster, correct line numbers for error reporting, optimized outputting, etc.)
  • ...