• Why is this grammar fragment nondeterministic?
• Does this rule match a sample input?
• Why is this grammar improperly matching this complete input?
• Why is there a syntax error given this input?
• Why is there no syntax error given this ungrammatical input?

See also the Romanian translation of this web page (by Web Geek Science)

Download ANTLRWorks 1.5.2 On Mac OS X you can just click on that jar and it will start up the GUI. Same for Windows unless you use IE (IE thinks it's a zip). On Linux, you have to save to the disk and run from the command line (read this tutorial for more information about launching ANTLRWorks). That jar includes all the other jars necessary to run it including ANTLR 3.5rc2, StringTemplate 4.0.7rc2, and StringTemplate 3.2.1. Note: ANTLRWorks requires Java 1.5 or later to run For Windows, Linux and Mac OS X Source code (BSD license) Previous Versions Take your pick from download directory.

Bugs Bugs: sorry, I am not fixing bugs anymore

Screen shots and movies Editor Window Grammar Interpreter Integrated Debugger Click the following link to watch the debugger in action: debugger.mp4 Ambiguous Path Visualization Decision DFA Visualization Use QuickTime or VideoLAN to view this video

Documentation Release notes Read-Me Online Help Read this simple "expression evaluator" tutorial How to run ANTLRWorks on Linux, Windows and Mac OS X How to setup IntelliJ to edit, run and debug ANTLRWorks How to build ANTLRWorks using ant How to generate syntax diagrams without GUI FAQ

Editor Single window editing Syntax highlighting Rule navigation tree Jump to rule or token definition Go To Rule Find usages of tokens or rules Find and Replace using regular expression Sensitive keyword, rule, and token auto-completion Rules and actions folding Tips and ideas Auto-indentation Refactoring - remove left recursion, extract or inline rule, etc. Show generated lexer or parser code using syntax coloring Syntax diagram display for lexer and parser rule Show unreachable alternative(s) in syntax diagram Display nondeterminism warning as ambiguous paths through the syntax diagram Highlight decision DFA Rule dependency graph Export syntax diagram, NFA and parse tree to bitmap image or EPS file Perforce integration emacs key bindings (Mac OS X only) Contextual menus Print

Grammar interpreter ANTLRWorks can immediately interpret a grammar and test it against some sample input--without generating anything! Great for rapid prototyping. You get the parse tree as a result of interpreting a grammar. Imagine passing some input to a rule in your grammar and instantly seeing how the rule matches the input. Dynamically interpreter any input text Display parse trees as list or graph

Grammar debugger ANTLR v3 has a sophisticated debug event mechanism that allows ANTLRWorks to follow along as a parser processes input. ANTLR v3 includes a well-defined protocol for communicating with remote parsers so ANTLRWorks can actually connect to a parser generated in any language with a socket library. We designed the debugger to work like TiVo: you can pause a running parser and then rewind it! Once a parse has completed, ANTLRWorks has a complete trace and allows the user to walk back and forth over the input stream like a video camera. Local or remote debugger Language agnostic Dynamic parse tree Dynamic AST Tree grammar debugging Lookahead highlighting Breakpoint in grammar Breakpoint in input text! Breakpoint on any events - LT, consume token, exception, etc. Step over rule Show corresponding grammar location and parse tree node for each input token Detachable panels