ext/ply/ANNOUNCE

   1 February 19, 2007
   2
   3                   Announcing :  PLY-2.3 (Python Lex-Yacc)
   4
   5                         http://www.dabeaz.com/ply
   6
   7 I'm pleased to announce a significant new update to PLY---a 100% Python
   8 implementation of the common parsing tools lex and yacc.  PLY-2.3 is
   9 a minor bug fix release, but also features improved performance.
  10
  11 If 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
  39 More information about PLY can be obtained on the PLY webpage at:
  40
  41                    http://www.dabeaz.com/ply
  42
  43 PLY is freely available and is licensed under the terms of the Lesser
  44 GNU Public License (LGPL).
  45
  46 Cheers,
  47
  48 David Beazley (http://www.dabeaz.com)