Python runtime

Python runtime package

The runtime package for Python is called antlr3. The package is pure Python and does not have any dependencies to non-standard modules.

Installation

1. Download the "Complete ANTLR 3.x Java binaries jar" from the ANTLR download page, extract it, and run the Python installer.
   • On a Linux shell:

     wget http://www.antlr.org/download/antlr-3.1.3.tar.gz
     tar xzf antlr-3.1.3.tar.gz
     cd antlr-3.1.3/runtime/Python
     sudo python setup.py install
     

2. Check your installation by using the Python shell:

   $ python
   Python 2.6.5 (r265:79063, Apr 16 2010, 13:57:41)
   [GCC 4.4.3] on linux2
   Type "help", "copyright", "credits" or "license" for more information.
   >>> import antlr3
   >>>
   

Differences from Java runtime

The package structure tries to mimic the Java runtime as close as possible. Translating import statements from Java to Python should be straight forward:

import org.antlr.runtime.*;
import org.antlr.runtime.tree.CommonTree;

from antlr3 import *
from antlr3.tree import CommonTree

The only difference is that a number of static names, which are members of various Java classes, are defined in the module namespace:

The API should be mostly identical to Java, with a few exceptions:

• The CommonToken constructor has a different signature than the (overloaded) Java version. It is advised to call it always with keyword arguments to avoid confusion:
  • CommonToken(type=None, channel=DEFAULT_CHANNEL, text=None, input=None, start=None, stop=None, oldToken=None)
• The overloaded TreeAdaptor.create() is available, but should not be used directly. Instead you should use
  • TreeAdaptor.createWithPayload(token)
  • TreeAdaptor.createFromToken(typeType, fromToken, text=None)
  • TreeAdaptor.createFromType(typeType, text)

There is also full API documentation available for the Python runtime.