What is AST transformation in Groovy?

An AST (Abstract Syntax Tree) transformation is code that runs during Groovy's compilation process to modify the program's structure before it's turned into bytecode - effectively generating or altering code automatically at compile time rather than at runtime.

Groovy ships many built-in AST transformations as annotations, like @ToString, @EqualsAndHashCode, and @Builder, each injecting the corresponding generated methods into a class without the developer writing that boilerplate by hand.

Because transformations happen at compile time, the generated code is part of the actual compiled bytecode with no runtime reflection overhead, unlike some annotation-processing approaches that rely on runtime inspection instead.

Invest now in Acorns!!! 🚀
Join Acorns and get your $5 bonus!

Acorns is a micro-investing app that automatically invests your "spare change" from daily purchases into diversified, expert-built portfolios of ETFs. It is designed for beginners, allowing you to start investing with as little as $5. The service automates saving and investing. Disclosure: I may receive a referral bonus.

Invest now!!! Get Free equity stock (US, UK only)!

Use Robinhood app to invest in stocks. It is safe and secure. Use the Referral link to claim your free stock when you sign up!.

The Robinhood app makes it easy to trade stocks, crypto and more.

Webull! Receive free stock by signing up using the link: Webull signup.