GEPs for Groovy

Here you can find the GEPs for the Groovy programming language:

• GEP-1: Groovy Enhancement Proposal

  Status: Final

• GEP-2: AST Builder Support

  Status: Final | Target: Groovy 1.7 | Comment: Included in Groovy but somewhat _superseded by macros_

• GEP-3: Command Expression based DSL

  Status: Final | Target: Groovy 1.8 or 2.0 | Comment: Included in Groovy and has been further enhanced

• GEP-4: AstBuilder AST Templates

  Status: Rejected | Comment: The approach used in Groovy macros was pursued instead

• GEP-5: File extension dependent AST transformations

  Status: Rejected | Comment: Groovy 1.8 instead adopted a general compiler configuration mechanism

• GEP-6: NIO2 Support for Groovy

  Status: Final | Comment: Delivered in Groovy 2.3

• GEP-7: JSON Support

  Status: Final | Comment: Delivered in Groovy 1.8

• GEP-8: Static type checking

  Status: Final | Comment: Delivered in Groovy 2.0 and enhanced in later versions

• GEP-9: Modularization

  Status: Final | Comment: Parts incorporated in Groovy 2.0

• GEP-10: Static compilation

  Status: Final | Comment: Delivered in Groovy 2.0 and enhanced in later versions

• GEP-11: Groovy 3 semantics and new MOP

  Status: Draft | Last modification: 2018-10-28

• GEP-12: SAM coercion

  Status: Final

• GEP-13: Sealed classes

  Status: Draft | Last modification: 2021-07-22

• GEP-14: Record classes

  Status: Draft | Last modification: 2021-10-26

• GEP-15: Compound assignment operator overloading

  Status: Draft | Last modification: 2026-04-28

• GEP-16: val type placeholder for final declarations

  Status: Draft | Last modification: 2026-04-12

• GEP-17: Consistent handling of internal properties via @Internal

  Status: Draft | Last modification: 2026-04-14

• GEP-18: Integrated Concurrency and Parallel Processing

  Status: Draft | Last modification: 2026-04-15

• GEP-19: Structural Pattern Matching in switch

  Status: Draft | Last modification: 2026-04-25

• GEP-20: Multi-assignment Destructuring

  Status: Draft | Last modification: 2026-04-25

• GEP-21: Broadening AST transform awareness under joint compilation

  Status: Draft | Last modification: 2026-04-30

In addition, smaller GEPs are tracked as issues in Jira:

• GROOVY-9442: GEP: Support for the new JDK14 string escape sequence (\s for single space)
• GROOVY-8431: toDebugString method as a core concept
• GROOVY-7957: Allow static compilation of builders that implement methodMissing / propertyMissing
• GROOVY-7956: Provide an AST transformation which improves named parameter support
• GROOVY-4384: Implement GEP-3: extended command expressions
• GROOVY-1884: GEP: Adding Bound Properties to GroovyBeans
• GROOVY-1709: GEP: Groovy Enhancement Proposal
• GROOVY-158: Multiple assignment