The Definitive ANTLR 4 Reference, 2nd Edition

Library Package Overview

ANTLR’s runtime consists of six packages, with most of the application-facing classes in the main org.antlr.v4.runtime package. By far the most common classes are the ones used to launch a parser on some input. Here is the typical code snippet for a grammar file called X.g and a parse-tree listener called MyListener that implements XListener:

XLexer lexer = new XLexer(input);
CommonTokenStream tokens = new CommonTokenStream(lexer);
XParser parser = new XParser(tokens);
ParseTree tree = parser.XstartRule();

ParseTreeWalker walker = new ParseTreeWalker();
MyListener listener = new MyListener(parser);
walker.walk(listener, tree);

We first encountered this in ​Integrating a Generated Parser into a Java ...