=========
Use CRF++
=========

This page describes a procedure that enables `CRF++ <http://crfpp.googlecode.com/svn/trunk/doc/index.html>`_ to be used with RaSC. CRF++ must be changed at the program level to perform input and output through file (for the changes, refer to :ref:`faq_modify_program`)．

The following describes a procedure to change the program by applying a patch to it so that CRF++ may be used as an RaSC service.


Change CRF++ to be RaSC-enabled
===============================

First, get the CRF++ source code.

.. code-block:: bash

   $ wget http://crfpp.googlecode.com/files/CRF%2B%2B-0.57.tar.gz
   $ tar zxvf CRF++-0.57.tar.gz

Then, get the patch file.

.. code-block:: bash

   $ wget https://alaginrc.nict.go.jp/rasc/resources/patch_rasc_crf.diff

Then, apply the patch.

.. code-block:: bash

   $ patch -p0 < patch_rasc_crf.diff

Then, build CRF++.

.. code-block:: bash

   $ cd CRF++-0.57
   $ ./configure
   $ make

These commands produce the executable binary ``crf_test``, which has been modified so that it can be used with RaSC.


Configure service XML for CRF++
===============================

In a service definition XML, describe a start command line that includes the path to and the model file of the executable binary (you can download the :download:`service XML <service_xml/CrfService.xml>`)．Modify ``___BASE_DIR___`` and ``___PATH_TO_MODEL_FILE___`` to the directory that actually includes ``crf_test`` and the path to the model file.

.. code-block:: xml
   :emphasize-lines: 8-10

   <?xml version="1.0" encoding="UTF-8"?>
   <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
   <beans>
     <bean id="target"
       class="jp.go.nict.langrid.servicecontainer.handler.TargetServiceFactory">
       <property name="service">
         <bean class="jp.go.nict.wisdom.wrapper.StdIOCommandService">
           <property name="cmdLine" value="___BASE_DIR___/crf_test -m ___PATH_TO_MODEL_FILE___ -" />
           <property name="delimiterIn" value="\n[END_OF_INPUT]\n" />
           <property name="delimiterOut" value="EOS\n" />
           <property name="delLastNewline" value="true" />
         </bean>
       </property>
     </bean>
   </beans>


- For ``cmdLine``, specify the path to and the model file for CRF that was created before by applying the patch. The last ``-`` means an option to accept the input data from standard input.
- For ``delimiterIn``, describe ``\n[END_OF_INPUT]\n`` because the patch has been applied to set the input delimiting character string to ``[END_OF_INPUT]``.
- Similarly, for delimiterOut, describe ``EOS\n`` because the patch has been applied to set the output delimiting character string to ``EOS\n``.
- Within the program, ``\n`` in this example will be replaced with an appropriate linefeed code suitable for each system.

For information on the procedure to start the service, refer to :doc:`rasc_core` or :doc:`rasc_basic`．