The ActionScript code generation target

Note: The ActionScript target was last synced with the 3.2 version of ANTLR, and is no longer being actively maintained.

The ActionScript target closely follows the Java target. The API and runtime behavior are consistent to the extent possible.

Please send bug reports, feedback, patches to the antlr-interest mailing list.


The runtime generates ActionScript 3 code designed to work with Flex version 2 or higher from Adobe. The runtime binary libraries are all compiled with the latest Flex 3.2 SDK.

To use generated code, you'll need to include ActionScript runtime package antlr3.swc in your library path. There are no other dependencies beyond the standard Flex libraries. Note, that the library contains some Adobe AIR class references, to use the library in a pure Flex project use the -library-path compiler option rather than the -include-library option when compiling from the command line.


Selecting ActionScript output

Just add language=ActionScript; to the options section of your grammar:

For a grammar T.g ANTLR3 will then create the files and which contain the classes TLexer and TParser (or just one of those, if you have a pure lexer/parser). For tree parsers, ANTLR3 creates containing the class T.

Specifying an ActionScript package for your recognizer

You can specify that your generated recognizer should be declared within a specific package as shown below. By default all recognizers are generated as top-level types with no enclosing package.

Using the generated classes

To use a grammar T.g:

For complex parsers, you may want to avoid creating the lexers and parsers each time you want to parse input. In this case you can do the following, which will reset the lexer and parser by setting the charStream or tokenStream property (as appropriate):

If you want to access the tokens types in your code, you'll have to import and access them from the lexer or parser module (e.g. TLexer.EOF, TLexer.IDENTIFIER):

Using tree parsers

For grammars T.g (parser and lexer) and TWalker.g (the tree parser):

API documentation

Reference documentation for the runtime package can be found at


This target currently supports the action scopes @lexer, @parser and @treeparser for global actions. The following action names are known:

  • package -Wrap the generated classes with the specified package.
  • header - Will be inserted right after ANTLRs own imports at the top of the generated file. Use it for import statements or any other functions/classes which you need in the package scope.
  • init - Will be inserted at the end of the constructor of the lexer/parser. Here you can setup your own instance attributes.
  • members - Will be inserted in the class body of the lexer/parser. This is the right place for custom methods and class attributes.

Unsupported features

  • -debug option: mostly useful for integration into ANTLRWorks.
  • output=template: StringTemplate has not been ported to ActionScript, so template-based recognizers are not supported.