zbx91 / python-spark

An Earley-Algorithm Context-free grammar Parser Toolkit

SPARK - An Earley Algorithm Parser toolkit.

SPARK stands for Scanning, Parsing, and Rewriting Kit. It uses Jay Earley's algorithm for parsing context free grammars, and comes with some generic Abstract Syntax Tree routines. There is also a prototype scanner which does its job by combining Python regular expressions.

The original version of this was written by John Aycock for his Ph.d thesis and was described in his 1998 paper: "Compiling Little Languages in Python" at the 7th International Python Conference. The current incarnation of this code is maintained (or not) by Rocky Bernstein.

Note: Earley algorithm parsers are almost linear when given an LR grammar. These are grammars which are left-recursive.

Installation

This uses setup.py, so it follows the standard Python routine:

python setup.py install # may need sudo
# or if you have pyenv:
python setup.py develop

Example

The github example directory has a worked-out examples; Package uncompyle6 uses this and contains a much larger example.

See Also

• features
• http://pages.cpsc.ucalgary.ca/~aycock/spark/ (Old and not very well maintained)
• https://pypi.python.org/pypi/uncompyle6/