GSP
Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Support
Contact Us
Online Help
Handbooks
Domain Status
Man Pages

FAQ
Virtual Servers
Pricing
Billing
Technical

Network
Facilities
Connectivity
Topology Map

Miscellaneous
Server Agreement
Year 2038
Credits
 

USA Flag

 

 

Man Pages


Manual Reference Pages  -  TEXT::MECAB (3)

.ds Aq ’

NAME

Text::MeCab - Alternate Interface To libmecab

CONTENTS

SYNOPSIS



  use Text::MeCab;
  my $mecab = Text::MeCab->new({
    rcfile             => $rcfile,
    dicdir             => $dicdir,
    userdic            => $userdic,
    lattice_level      => $lattice_level,
    all_morphs         => $all_morphs,
    output_format_type => $output_format_type,
    partial            => $partial,
    node_format        => $node_format,
    unk_format         => $unk_format,
    bos_format         => $bos_format,
    eos_format         => $eos_format,
    input_buffer_size  => $input_buffer_size,
    allocate_sentence  => $allocate_sentence,
    nbest              => $nbest,
    theta              => $theta,
  });

  for (my $node = $mecab->parse($text); $node; $node = $node->next) {
     # See perdoc for Text::MeCab::Node for list of methods
     print $node->surface, "\n";
  }

  # use constants
  use Text::MeCab qw(:all);
  use Text::MeCab qw(MECAB_NOR_NODE);

  # check what mecab version we compiled against?
  print "Compiled with ", &Text::MeCab::MECAB_VERSION, "\n";



DESCRIPTION

libmecab (http://mecab.sourceforge.ne.jp) already has a perl interface built with it, so why a new module? I just feel that while a subtle difference, making the perl interface through a tied hash is just... weird.

So Text::MeCab gives you a more natural, Perl-ish way to access libmecab!

WARNING: Version 0.20000 has only been tested against libmecab 0.96.

Text::MeCab AND FORMATS

mecab allows users to specify an output format, via --*-format options. These are respected ONLY if you use the format() method:



  my $mecab = Text::MeCab->new({
    output_format_type => "user",
    node_format => "%m %pn"
  });

  for(my $node = $mecab->parse($text); $node; $node = $node->next) {
    print $node->format($mecab);
  }



Note that you also need to set the output_format_type parameter as well.

Text::MeCab AND SCOPING

[NOTE: The memory management issue has been changed since 0.09]

libmecab’s default behavior is such that when you analyze a text and get a node back, that node is tied to the mecab tagger object that performed the analysis. Therefore, when that tagger is destroyed via mecab_destroy(), all nodes that are associated to it are freed as well.

Text::MeCab defaults to the same behavior, so the following won’t work:



  sub get_mecab_node {
     my $mecab = Text::MeCab->new;
     my $node  = $mecab->parse($_[0]);
     return $node;
  }

  my $node = get_mecab_node($text);



By the time get_mecab_node() returns, the Text::MeCab object is DESTROY’ed, and so is $node (actually, the object exists, but it will complain when you try to access the node’s internals, because the C struct that was there has already been freed).

In such cases, use the dclone() method. This will copy the *entire* node structure and create a new Text::MeCab::Node::Cloned instance.



  sub get_mecab_node {
     my $mecab = Text::MeCab->new;
     my $node  = $mecab->parse($_[0]);
     return $node->dclone();
  }



The returned Text::MeCab::Node::Cloned object is exactly the same as Text::MeCab::Node object on the surface. It just uses a different but very similar C struct underneath. It is blessed into a different namespace only because we need to use a different memory management strategy.

Do be aware of the memory issue. You WILL use up twice as much memory.

Also please note that if you try the first example, accessing the node *WILL* result in a segfault. This is *NOT* a bug: it’s a feature :) While it is possible to control the memory management such that accessing a field in a node that has already expired results in a legal croak(), we do not go to the length to ensure this, because it will result in a performance penalty.

Just remember that unless you dclone() a node, then you are NOT allowed to access it when the original tagger goes out scope:



   {
       my $mecab = Text::MeCab->new;
       $node = $mecab->parse(...);
   }

   $node->surface; # segfault!!!!



Always remember to dclone() before doing this!

PERFORMANCE

Belows is the result of running tools/benchmark.pl on my PowerBook:



  daisuke@beefcake Text-MeCab$ perl tools/benchmark.pl
               Rate      mecab text_mecab
  mecab      5.53/s         --       -63%
  text_mecab 14.9/s       170%         --



METHODS

    new HASHREF | LIST

Creates a new Text::MeCab instance.

You can either specify a hashref and use named parameters, or you can use the exact command line arguments that the mecab command accepts.

Below is the list of accepted named options. See the man page for mecab for details about each option.
<B>rcfileB>
<B>dicdirB>
<B>lattice_levelB>
<B>all_morphsB>
<B>output_format_typeB>
<B>partialB>
<B>node_formatB>
<B>unk_formatB>
<B>bos_formatB>
<B>eos_formatB>
<B>input_buffer_sizeB>
<B>allocate_sentenceB>
<B>nbestB>
<B>thetaB>

    parse SCALAR

Parses the given text via mecab, and returns a Text::MeCab::Node object.

    ENCODING



  my $encoding = Text::MeCab::ENCODING



Returns the encoding of the underlying mecab library that was detected at compile time.

    MECAB_VERSION

The version number from libmecab’s mecab_version()

    MECAB_TARGET_VERSION

    MECAB_TARGET_MAJOR_VERSION

    MECAB_TARGET_MINOR_VERSION

The version number detected at compile time of Text::MeCab.

    MECAB_CONFIG

Path to mecab-config, if available.

SEE ALSO

http://mecab.sourceforge.ne.jp

LICENSE

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

See http://www.perl.com/perl/misc/Artistic.html

AUTHOR

Copyright (c) 2006-2008 Daisuke Maki <daisuke@endeworks.jp> All rights reserved.
Search for    or go to Top of page |  Section 3 |  Main Index


perl v5.20.3 TEXT::MECAB (3) 2016-04-03

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with manServer 1.07.