Introduction

The tokenizer tokenizes a text into sentences and words.

Confused by some terminology?

This software is part of a larger collection of natural language processing tools known as "the OpeNER project". You can find more information about the project at the OpeNER portal. There you can also find references to terms like KAF (an XML standard to represent linguistic annotations in texts), component, cores, scenario's and pipelines.

Quick Use Example

Installing the tokenizer can be done by executing:

gem install tokenizer

Please bare in mind that all components in OpeNER take KAF as an input and output KAF by default.

Command line interface

You should now be able to call the tokenizer as a regular shell command: by its name. Once installed the gem normally sits in your path so you can call it directly from anywhere.

Tokenizing some text:

echo "This is English text" | tokenizer -l en --no-kaf

Will result in

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<KAF version="v1.opener" xml:lang="en">
  <kafHeader>
    <linguisticProcessors layer="text">
      <lp name="opener-sentence-splitter-en" timestamp="2013-05-31T11:39:31Z" version="0.0.1"/>
      <lp name="opener-tokenizer-en" timestamp="2013-05-31T11:39:32Z" version="1.0.1"/>
    </linguisticProcessors>
  </kafHeader>
  <text>
    <wf length="4" offset="0" para="1" sent="1" wid="w1">This</wf>
    <wf length="2" offset="5" para="1" sent="1" wid="w2">is</wf>
    <wf length="7" offset="8" para="1" sent="1" wid="w3">English</wf>
    <wf length="4" offset="16" para="1" sent="1" wid="w4">text</wf>
  </text>
</KAF>

The available languages for tokenization are: English (en), German (de), Dutch (nl), French (fr), Spanish (es), Italian (it)

KAF input format

The tokenizer is capable of taking KAF as input, and actually does so by default. You can do so like this:

echo "<?xml version='1.0' encoding='UTF-8' standalone='no'?><KAF version='v1.opener' xml:lang='en'><raw>This is what I call, a test!</raw></KAF>" | tokenizer

Will result in

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<KAF version="v1.opener" xml:lang="en">
  <kafHeader>
    <linguisticProcessors layer="text">
      <lp name="opener-sentence-splitter-en" timestamp="2013-05-31T11:39:31Z" version="0.0.1"/>
      <lp name="opener-tokenizer-en" timestamp="2013-05-31T11:39:32Z" version="1.0.1"/>
    </linguisticProcessors>
  </kafHeader>
  <text>
    <wf length="4" offset="0" para="1" sent="1" wid="w1">this</wf>
    <wf length="2" offset="5" para="1" sent="1" wid="w2">is</wf>
    <wf length="2" offset="8" para="1" sent="1" wid="w3">an</wf>
    <wf length="7" offset="11" para="1" sent="1" wid="w4">english</wf>
    <wf length="4" offset="19" para="1" sent="1" wid="w5">text</wf>
  </text>
</KAF>

If the argument -k (--kaf) is passed, then the argument -l (--language) is ignored.

Webservices

You can launch a language identification webservice by executing:

tokenizer-server

This will launch a mini webserver with the webservice. It defaults to port 9292, so you can access it at http://localhost:9292.

To launch it on a different port provide the -p [port-number] option like this:

tokenizer-server -p 1234

It then launches at http://localhost:1234

Documentation on the Webservice is provided by surfing to the urls provided above. For more information on how to launch a webservice run the command with the --help option.

Daemon

Last but not least the tokenizer comes shipped with a daemon that can read jobs (and write) jobs to and from Amazon SQS queues. For more information type:

tokenizer-daemon --help

Description of dependencies

This component runs best if you run it in an environment suited for OpeNER components. You can find an installation guide and helper tools in the OpeNER installer and an installation guide on the Opener Website.

At least you need the following system setup:

Dependencies for normal use:

• Perl 5
• MRI 1.9.3

Dependencies if you want to modify the component:

• Maven (for building the Gem)

Language Extension

The tokenizer module is a wrapping around a Perl script, which performs the actual tokenization based on rules (when to break a character sequence). The tokenizer already supports a lot of languages. Have a look to the core script to figure out how to extend to new languages.

The Core

The component is a fat wrapper around the actual language technology core. The core is a rule based tokenizer implemented in Perl. You can find the core technologies in the following repositories:

• tokenizer-base

Where to go from here

• Check the project website
• Checkout the webservice

Report problem/Get help

If you encounter problems, please email support@opener-project.eu or leave an issue in the issue tracker.

Contributing

1. Fork it ( http://github.com/opener-project/tokenizer/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request