BoxLang AST Visitor

A base visitor implementation for Boxlang parsing. By creating an instance of a custom visitor class which extends our core class, you can "visit" a top level AST node, which will recursivley visit each node in the tree. By overriding methods in your custom visitor, you can choose which nodes you want to "visit". The convention is to create a method named visit<NameOfNode> where the name of the Node is the name of the Java class from the BoxLang AST.

https://github.com/ortus-boxlang/BoxLang/tree/development/src/main/java/ortus/boxlang/compiler/ast

Void Visitor

A void visitor does not return anything from each visitXXX() method, but it can gather information about the nodes or mutate them in place.

Example visitor classs

class extends="bxmodules.bxASTVisitor.models.VoidBoxVisitor" {
	
	/**
	* visit each function declaration
	* https://github.com/ortus-boxlang/BoxLang/blob/development/src/main/java/ortus/boxlang/compiler/ast/statement/BoxFunctionDeclaration.java
	*/
	function visitBoxFunctionInvocation(node) {
		// Log out the name of the function 
		println( "Function Name: " & node.getName())
		// Must call this, or we won't recurse into children nodes
		visitChildren(node);
	}
	
}

Acquire the AST for some code and visit it like so:

import ortus.boxlang.compiler.parser.Parser;
result = new Parser().parse( "echo( 'hello world' )" )
if( !result.getIssues().isEmpty() ) {
	println( result.getIssues() );
	throw( "Parsing failed" );
}
new MyVisitor().visit( result.getRoot() );

This will output

Function Name: echo

as the AST of the code will have a function invocation for echo().

Parse a file like so, using the AST in the same manner as above.

import java.io.File;
import ortus.boxlang.compiler.parser.Parser;
result = new Parser().parse( new File( expandPath( 'MyClass.bx' ) ) )