ANNOUNCE (1870B)
1November 1, 2006 2 3 Announcing : PLY-2.2 (Python Lex-Yacc) 4 5 http://www.dabeaz.com/ply 6 7I'm pleased to announce a significant new update to PLY---a 100% Python 8implementation of the common parsing tools lex and yacc. PLY-2.2 is 9a minor update that fixes a few bugs and adds some new capabilities. 10 11If you are new to PLY, here are a few highlights: 12 13- PLY is closely modeled after traditional lex/yacc. If you know how 14 to use these or similar tools in other languages, you will find 15 PLY to be comparable. 16 17- PLY provides very extensive error reporting and diagnostic 18 information to assist in parser construction. The original 19 implementation was developed for instructional purposes. As 20 a result, the system tries to identify the most common types 21 of errors made by novice users. 22 23- PLY provides full support for empty productions, error recovery, 24 precedence rules, and ambiguous grammars. 25 26- Parsing is based on LR-parsing which is fast, memory efficient, 27 better suited to large grammars, and which has a number of nice 28 properties when dealing with syntax errors and other parsing 29 problems. Currently, PLY can build its parsing tables using 30 either SLR or LALR(1) algorithms. 31 32- PLY can be used to build parsers for large programming languages. 33 Although it is not ultra-fast due to its Python implementation, 34 PLY can be used to parse grammars consisting of several hundred 35 rules (as might be found for a language like C). The lexer and LR 36 parser are also reasonably efficient when parsing normal 37 sized programs. 38 39More information about PLY can be obtained on the PLY webpage at: 40 41 http://www.dabeaz.com/ply 42 43PLY is freely available and is licensed under the terms of the Lesser 44GNU Public License (LGPL). 45 46Cheers, 47 48David Beazley (http://www.dabeaz.com)