NAME

    re::engine::TRE - TRE regular expression engine

VERSION

    version 0.09

SYNOPSIS

        use re::engine::TRE max_cost => 1;
    
        if ("A pearl is a hard object produced..." =~ /\(Perl\)/i) {
            say $1; # "pearl"
        }

DESCRIPTION

    Replaces Perl's regex engine in a given lexical scope with POSIX
    regular expressions provided by the TRE regular expression library.
    tre-0.8.0 <http://laurikari.net/tre/download/> is shipped with this
    module.

PRAGMA OPTIONS

      * cost_ins: The default cost of an inserted character, that is, an
      extra character in string (default: 1).

      * cost_del: The default cost of a deleted character, that is, a
      character missing from string (default: 1).

      * cost_subst: The default cost of a substituted character (default:
      1).

      * max_cost: The maximum allowed cost of a match. If this is set to
      zero, an exact matching is searched for (default: 0).

      * max_ins: Maximum allowed number of inserted characters (default:
      unspecified).

      * max_del: Maximum allowed number of deleted characters (default:
      unspecified).

      * max_subst: Maximum allowed number of substituted characters
      (default: unspecified).

      * max_err: Maximum allowed number of errors (inserts + deletes +
      substitutes; default: unspecified).

    Set any value to -1 to represent "unspecified, but very high".

REFERENCES

 Algorithm & Implementation

      * Bitap algorithm <https://en.wikipedia.org/wiki/Bitap>

      * Introduction to the TRE regexp matching library.
      <http://laurikari.net/tre/about/>

 Salvaged several parts from

      * re::engine::PCRE (recent Perl compatibility)

      * re::engine::RE2 (parameter passing)

      * String::Approx (tests for approximate matching)

AUTHOR

    Ævar Arnfjörð Bjarmason <avar@cpan.org>

COPYRIGHT AND LICENSE

    This software is copyright (c) 2014 by Ævar Arnfjörð Bjarmason.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.