ERE.pm

Copyright (C) 2012, Loïc Jonas Etienne


OVERVIEW

Pure perl module for:

  - Parsing POSIX Extended Regular Expressions (ERE) into
    Non-Deterministic Finite Automata (nfa)

  - Manipulating nfa (and-ing, or-ing, concatenating)
    and inspecting them (transparent, documented data structure)

  - Computing Deterministic Finite Automata (dfa) from nfa
    (powerset construction)

  - Computing minimal dfa from dfa
    (Hopcrofts's algorithm)

  - Computing ERE or Perl Regular Expressions from nfa or dfa
    (Warshall algorithm)

  - Heuristically deriving from a nfa or dfa (possibly weaker) constraints
    suitable for display in a graphical user interface,
    i.e. a sequence of widgets of type 'free text' and 'drop down';
    Example: '^(abc|def).*' => $nfa => [['abc', 'def'], 'free text']


INSTALLATION

    See the file INSTALL

VERSIONS

    0.01 initial version
    0.02 minor documentation improvements
         fixes for bugs revealed by perl 17:
           - results independent of the hash key order
           - improved prefix/suffix factorization
           - improved test cases
    0.03 minor documentation improvements
         new quote function
         improved ere parsing (a+ as a*a or aa* depending on the context)
         improved tree construction/factorization
         additional test cases
         bug fixes:
           - _tree_to_regex missed a starification
           - drop-downs including the empty string were discarded
    0.04 bug fixes
           - oversimplification in _nfa_concat corrected


AUTHOR

    Loïc Jonas Etienne <loic.etienne@tech.swisssign.com>


LICENSE INFORMATION

    This module is free software; you can redistribute it and/or modify it
    under the terms of the Artistic License 2.0. For details, see the full
    text of the license in the file LICENSE.

    This program is distributed in the hope that it will be useful, but it
    is provided "as is" and without any express or implied warranties. For
    details, see the full text of the license in the file LICENSE.