ANNOUNCE revision 4479 
1February 19, 2007
2
3                  Announcing :  PLY-2.3 (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-2.3 is
9a minor bug fix release, but also features improved performance.
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
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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)