The Omega parsing framework

## Project description

**Author:**Timothy Allen <screwtape@froup.com>**Website:**https://gitorious.org/python-omega/**Mailing-list:**<python.omega@librelist.com>**Licence:**The Omega package and all associated documentation and example code are placed under the GNU GPLv3. See the included file LICENCE for details.

## Introduction

Omega is a framework designed to help you build parsers for text and binary data. It creates a recursive-descent/Parsing-Expression-Grammar parser given a description of the file-format in the concise Omega language, but if your file-format can’t be described in pure Omega, it’s easy to extend with Python.

For example, here’s a very simple parser for arithmetic expressions:

>>> import omega >>> class ArithmeticParser(omega.BaseParser): ... __grammar = """ ... digit = '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' ... | '8' | '9' ; ... term = digit+:ds -> (int("".join(ds))) ... | '(' sum:s ')' -> (s) ... ; ... product = term:a '*' product:b -> (a * b) ... | term:a '/' product:b -> (a / b) ... | term ... ; ... sum = product:a '+' sum:b -> (a + b) ... | product:a '-' sum:b -> (a - b) ... | product ... ; ... """

And here it is in action:

>>> ArithmeticParser.match("1") 1 >>> ArithmeticParser.match("1+1") 2 >>> ArithmeticParser.match("6*9") 54 >>> ArithmeticParser.match("2+3*4") 14 >>> ArithmeticParser.match("(2+3)*4") 20

Omega is heavily based on ideas from Alessandro Warth’s [OMeta package][1] for Smalltalk and JavaScript, but translated to fit as naturally as possible into Python.

## Requirements

Omega is a pure-Python package, and requires only Python 2.7 to be installed. It will likely be ported to Python 3.0 in the near future.

## What’s In The Box

- README.md is this file.
- TODO.md is a list of possible future additions to the package.
- LICENCE is the full text of the licence this software is released under, the GPLv3.
- setup.py is the standard Python packaging script.
- docs is a subdirectory containing all the documentation for Omega, including language and library references, a Python API reference, and a tutorial.
- examples is a subdirectory containing various self-contained example parsers written in Omega.
- omega is the Python package itself.

## Installation

Omega uses the standard distutils packaging system for Python, so if you have a source tarball, you should be able to install it with:

python setup.py install

…and of course all the other standard distutils commands are available.

## Documentation

The complete documentation is packaged with Omega source releases, and is also available online at https://gitorious.org/python-omega/pages/Home

## Project details

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Filename, size & hash SHA256 hash help | File type | Python version | Upload date |
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