setuptools-antlr 0.4.0

Setuptools command for generating ANTLR based parsers.

Overview

A setuptools command for generating ANTLR based parsers.

This is an extension for setuptools integrating the famous ANTLR parser generator into the Python packaging process. It encapsulates the Java based generator of ANTLR and provides the user a single command to control the generation process.

All command line options of ANTLR are also available through the setuptools command. The user has the choice to pass the options on the command line or configure ANTLR in a dedicated section in the setup.cfg file.

ANTLR grammars and its dependencies like imported grammars or token files are automatically detected. For each grammar a Python package will be generated during execution of the antlr command.

Installation

setuptools-antlr can be installed in various ways. To run it the following prerequisites have to be fulfilled:

• Python 3.5+

• setuptools

• Java JRE 1.7+

The source distribution is already shipped with ANTLR 4.7.1. It isn’t necessary to download ANTLR additionally.

After installation, the used Python environment has a new setuptools command called antlr.

From Source Code

> git clone https://github.com/ferraith/setuptools-antlr.git
> cd setuptools-antlr
> pip install .

From PyPI

> pip install setuptools-antlr

From GitHub Releases

> pip install <setuptools-antlr_wheel>

Usage

Integration

For a smooth user experience it’s recommended to pass setuptools-antlr using the setup_requires argument of setup function. Additionally each generated parser requires the ANTLR runtime library which should be added to install_requires argument:

setup(
    ...
    setup_requires=['setuptools-antlr'],
    install_requires=['antlr4-python3-runtime']
    ...
)

Before generating a parser setuptools will automatically check the Python environment and download setuptools-antlr from PyPI if it’s missing. During the installation of the project package pip will install antlr4-python3-runtime into the Python environment.

Configuration

setuptools-antlr provides two possibilities to configure the ANTLR parser generator.

All options of ANTLR can be passed on the command line after the antlr command:

> python setup.py antlr --visitor

It’s also possible to pass several options to ANTLR or execute multiple commands at once:

> python setup.py antlr --visitor --grammar-options "superClass=Abc tokenVocab=SomeLexer" bdist_wheel

See python setup.py antlr --help for available command line options:

> python setup.py antlr --help
...
Options for 'AntlrCommand' command:
  --grammars (-g)       specify grammars to generate parsers for
  --output (-o)         specify directories where output is generated
  --atn                 generate rule augmented transition network diagrams
  --encoding            specify grammar file encoding e.g. euc-jp
  --message-format      specify output style for messages in antlr, gnu, vs2005
  --long-messages       show exception details when available for errors and
                        warnings
  --listener            generate parse tree listener (default)
  --no-listener         don't generate parse tree listener
  --visitor             generate parse tree visitor
  --no-visitor          don't generate parse tree visitor (default)
  --depend              generate file dependencies
  --grammar-options     set/override a grammar-level option
  --w-error             treat warnings as error
  --x-dbg-st            launch StringTemplate visualizer on generated code
  --x-dbg-st-wait       wait for STViz to close before continuing
  --x-force-atn         use the ATN simulator for all predictions
  --x-exact-output-dir  output goes into -o directories regardless of paths/package
  --x-log               dump lots of logging info to antlr-<timestamp>.log
...

The ANTLR documentation explains all command line options and grammar options in detail.

Apart from passing options on the command line it’s also possible to add a dedicated [antlr] section to setup.cfg. The following example section contains all available options:

[antlr]
# Specify grammars to generate parsers for; default: None
#grammars = <grammar> [<grammar> ...]
# Specify directories where all output is generated; default: ./
output = default=gen
# Generate DOT graph files that represent the internal ATN data structures (yes|no); default: no
#atn = no
# Specify grammar file encoding; default: utf-8
#encoding = utf-8
# Specify output style for messages in antlr (antlr|gnu|vs2005); default: antlr
#message-format = antlr
# Show exception details when available for errors and warnings (yes|no); default: no
#long-messages = no
# Generate a parse tree listener (yes|no); default: yes
#listener = yes
# Generate parse tree visitor (yes|no); default: no
visitor = yes
# Generate file dependencies (yes|no); default: no
#depend = no
# Set/override grammar-level options (<option>=<value> [<option>=value ...]); default: language=Python3
grammar-options = superClass=Abc
                  tokenVocab=SomeLexer
# Treat warnings as errors (yes|no); default: no
#w-error = no
# Launch StringTemplate visualizer on generated code (yes|no); default: no
#x-dbg-st = no
# Wait for STViz to close before continuing
#x-dbg-st-wait = no
# All output goes into -o dir regardless of paths/package (yes|no); default: no
#x-exact-output-dir = no
# Use the ATN simulator for all predictions (yes|no); default: no
#x-force-atn = no
# Dump lots of logging info to antlr-<timestamp>.log (yes|no); default: no
#x-log = no

A reference configuration is provided in the resources directory.

Sample

Besides the setuptools-antlr source code a sample project called foobar is provided in the samples directory. This sample consists of the two ANTLR grammars Foo and Bar. During the execution of setuptools-antlr two Python packages will be generated into the foobar package directory containing a parser for each grammar.

To generate parsers for both grammars and build a foobar wheel package execute the following command:

> python setup.py antlr bdist_wheel