What is an AST

The acronym AST is shorthand for the abstract syntax tree. During the compilation process, the Groovy compiler groovyc will generate interim data structures that represent the code that is being compiled. The main data structure that the complier produces is the AST. The AST is quite literally an abstract syntax tree. In other words, it is a tree structure in memory that describes the syntax of the code being compiled. To illustrate this, let's take a simple example:

class Foo {
    def barValue

    def bar() {
        return barValue
    }
}

The compiler will parse this code and turn it into a tree structure to represent the syntax of the code. At the top of the tree is a node, which represents the class declaration. This node is represented by the Groovy AST class ClassNode. The class node will have several child nodes of the type ConstructorNode, MethodNode, FieldNode, and PropertyNode depending on what phase of compilation we are at.

Note

The major elements of Groovy AST...