ANTLR: Is there a simple example?

Question

I\'d like to get started with ANTLR, but after spending a few hours reviewing the examples at the antlr.org site, I still can\'t get a clear understanding of the grammar to

Answer 1

At https://github.com/BITPlan/com.bitplan.antlr you'll find an ANTLR java library with some useful helper classes and a few complete examples. It's ready to be used with maven and if you like eclipse and maven.

https://github.com/BITPlan/com.bitplan.antlr/blob/master/src/main/antlr4/com/bitplan/exp/Exp.g4

is a simple Expression language that can do multiply and add operations. https://github.com/BITPlan/com.bitplan.antlr/blob/master/src/test/java/com/bitplan/antlr/TestExpParser.java has the corresponding unit tests for it.

https://github.com/BITPlan/com.bitplan.antlr/blob/master/src/main/antlr4/com/bitplan/iri/IRIParser.g4 is an IRI parser that has been split into the three parts:

1. parser grammar
2. lexer grammar
3. imported LexBasic grammar

https://github.com/BITPlan/com.bitplan.antlr/blob/master/src/test/java/com/bitplan/antlr/TestIRIParser.java has the unit tests for it.

Personally I found this the most tricky part to get right. See http://wiki.bitplan.com/index.php/ANTLR_maven_plugin

https://github.com/BITPlan/com.bitplan.antlr/tree/master/src/main/antlr4/com/bitplan/expr

contains three more examples that have been created for a performance issue of ANTLR4 in an earlier version. In the meantime this issues has been fixed as the testcase https://github.com/BITPlan/com.bitplan.antlr/blob/master/src/test/java/com/bitplan/antlr/TestIssue994.java shows.